THE  ROMANCE 
OF  MODERN 
RAILWAYS 


THOMAS 

N 


THE   ROMANCE 
OF   MODERN   RAILWAYS 


By  permission  of] 


The  L.  &  N.W.  Railway. 


A  RAILWAY  TRAVELLING  CRANE. 


Here  we  see  a  steam  crane  of  a  kind  largely  used  upon  railways.  It  can  travel  upon  the 
rails  just  like  any  railway  vehicle,  in  fact  it  can  form  part  of  a  fast  train.  When  not  in  use 
the  tall  "  jib  "  is  lowered  until  it  rests  flat  upon  a  truck  which  is  provided  for  the  purpose. 
When  at  work,  as  is  clearly  shown,  it  is  clipped  down  upon  the  rails  and  also  steadied  by 
timbers  upon  the  ballast. 

A  crane,  an  engine  and  a  few  vans  with  tools,  form  the  "  breakdown  train." 


THE    ROMANCE    OF 
MODERN    RAILWAYS 


THE  STORY  OF  MECHANICAL  LOCOMOTION,  WITH 
A  DESCRIPTION  OF  THE  CONSTRUCTION  &>  WORKING 
OF  THE  MOST  UP-TO-DATE  INVENTIONS,  APPLIANCES 
AND  DEVICES  FOR  SECURING  SPEED,  FACILITY  AND 
SAFETY  IN  OPERATION 


BY 


T.   W.    CORBIN 


AUTHOR    OF 
;  ENGINEERING    OF    TO-DAY,"    "MECHANICAL    INVENTIONS    OF    TO-DAY, 


WITH    MANY    ILLUSTRATIONS    &   DIAGRAMS 


PHILADELPHIA 
J.    B.    LIPPINCOTT    COMPANY 

LONDON  :   SEELEY,  SERVICE  fif  CO.,  LTD. 
1922 


M 


PREFACE 

OST  middle-aged  men  of  to-day  can  remember 
the  time  when  their  one  boyish  ambition  was 
to  be  an  engine-driver  ;  but  their  sons  found 
a  rival  interest  in  the  flying  machine  and  desired 
above  all  things  to  be  airmen. 

Flying  and  flying  machines,  however,  have  not  and 
cannot  have  so  many  interesting  features  as  are  to 
be  found  upon  engines  and  trains,  with  the  result  that 
the  interest  has  swung  back  to  the  railway,  and  most 
boys  of  to-day  are  as  keen  about  them  as  ever  their 
fathers  were. 

It  is  for  such  boys  that  this  book  is  intended  more 
than  anyone  else,  but  it  is  hoped,  nevertheless,  that 
it  may  make  an  even  wider  appeal.  The  writer  knows 
an  uncle  who  regularly  buys  a  certain  boys'  periodical. 
He  buys  it,  of  course,  to  give  to  his  nephew,  but  his 
friends  notice  that  he  always  reads  it  through  him- 
self first,  and,  although  this  book  may  be  intended 
for  the  sons  and  nephews,  it  is  quite  possible  that 
some  fathers  and  uncles  may  find  it  to  their  liking. 

The  writing  of  it  has  been  a  labour  of  love,  and  if 
all  readers  get  the  same  pleasure  in  reading  it  which 
the  writer  got  in  writing  it,  it  is  going  to  add  largely 
to  the  sum  of  human  happiness. 

The  writer  wishes  to  take  this  opportunity  of  thank- 
ing several  of  his  engineering  friends  ancTalso  a  number 

ii 

465255 


PREFACE 

of  railway  companies  and  manufacturing  firms  who 
have  supplied  him  with  technical  information  or 
photographs.  In  most  cases  a  reference  to  these 
helpers  appears  in  the  text,  and  it  is  hoped  that  they 
will  accept  that  as  a  grateful  acknowledgment  of 
their  kindness. 

Thanks  are  due  for  the  illustrations  provided  by 
the  Westinghouse  Brake  and  Saxby  Signal  Company, 
of  London. 


12 


CONTENTS 

CHAPTER   I 

PAGE 

HISTORICAL  AND  PROPHETIC       .         .         •         •         .17 

CHAPTER   II 
RAILWAY  PIONEERING 28 

CHAPTER   III 
WHERE  THE  LOCOMOTIVES  ARE  MADE         ...       39 

CHAPTER   IV 
How  A  LOCOMOTIVE  WORKS 60 

CHAPTER   V 
COMPOUND  LOCOMOTIVES 77 

CHAPTER   VI 
OIL-DRIVEN  LOCOMOTIVES  .....       86 

CHAPTER   VII 

BRAKES  :  How  THEY  WORK       .....       94 

CHAPTER   VIII 
THE  CONSTRUCTION  or  A  BRITISH  RAILWAY        .         .108 

CHAPTER   IX 
How  RAILS  ARE  MADE 122 

CHAPTER   X 
THE  STORY  OF  THE  BRIDGES     ...  .137 

CHAPTER   XI 

How  SINGLE  LINES  ARE  WORKED      .         .         •          .150 

13 


CONTENTS 

CHAPTER   XII  PAQB 

RAILWAY  SIGNALS     .          .          ,          .          .          .          .158 

CHAPTER   XIII 
AUTOMATIC  SIGNALLING     .         .         .         .         .         .175 

CHAPTER   XIV 
THE  SIGNALLING  OF  A  LARGE  TEBMIJTUS    .         .         .192 

CHAPTER   XV 
RAILWAYS  IN  FOGGY  WEATHER          .         .         .         .201 

CHAPTER   XVI 
TRAFFIC  CONTROL 215 

CHAPTER   XVII 
THE  TUBE  RAILWAY 230 

CHAPTER   XVIII 
WONDERS  OF  THE  UNDERGROUND       .         .         .         .241 

CHAPTER   XIX 
ELECTRIC  TRAINS  AND  HOW  THEY  ARE  DRIVEN  .         .     255 

CHAPTER   XX 
A  RAILWAY  IN  THE  AIR 271 

CHAPTER   XXI 
FIGHTING  NATURE  IN  CANADA 284 

CHAPTER   XXII 
LONG  ALPINE  TUNNELS  295 


INDEX 307 


LIST   OF   ILLUSTRATIONS 

A  TRAVELLING  CRANE       .....      Frontispiece 

FACING   PAGE 

MAKING  A  RAILWAY  CARRIAGE  .         .         .         .32 

A  REMARKABLE  LOCOMOTIVE  ON  THE  MIDLAND  .       48 

G.W.R.  EXPRESS  PASSENGER  ENGINE         ...       49 

A  LARGE  TANK  ENGINE 56 

A  DOUBLE  LOCOMOTIVE     ......       57 

A  FLOATING  RAILWAY 88 

CAB  INDICATOR 96 

AUTOMATIC  TRAIN  STOP    .          .         .         .         .         .104 

A  STRIKING  CONTRAST 112 

SAWING  COLD  STEEL          .         .         .         .          .         .128 

LOFTIEST  BRIDGE  EAST  OF  THE  ROCKY  MOUNTAINS     .     144 
THE  NEWEST  KIND  OF  SIGNAL  .         .         .          .160 

A  BRIDGE  OF  SIGNALS 168 

ILLUMINATED  DIAGRAM  OF  SIGNALS    .          .         .         .176 

FOG  SIGNALS 208 

A  BUSY  SPOT 224 

KEEPING  THE  TUNNELS  CLEAN  ....     232 

WHERE  DO  You  WANT  TO  Go  ?          .         .         .         .     240 

A  MOVING  STAIRCASE         .         .         .         .         .          .  •  248 

AN  ESCALATOR  IN  COURSE  OF  CONSTRUCTION      .         .     256 

THE  QUEEN'S  CARRIAGE 264 

A  RAILWAY  IN  THE  AIR 272 

TRACK-LAYING  MACHINE    ......     288 

15 


CHAPTER  I 
HISTORICAL   AND   PROPHETIC 

THE  history  of  the  Railway  is  not  a  very 
long  one.  About  a  hundred  years  will  cover 
it,  and  that,  by  comparison  with  most  historical 
periods,  is  very  short. 

It  is  interesting  to  picture  to  oneself  the  changes 
which  have  been  brought  about  by  the  railway  and 
then  to  deduct,  as  it  were,  those  changes  from  our 
present  condition,  thereby  bringing  ourselves  back 
to  that  time  when  we  were  without  railways. 

Travelling  in  those  days  must  have  been  very 
wearisome,  except  for  very  short  journeys.  To  travel 
a  hundred  miles  by  coach,  possibly  on  the  top  at 
night  and  in  the  depth  of  winter,  is  a  prospect  the 
mere  suggestion  of  which  makes  us  shudder.  But 
then,  we  have  learnt  what  it  is  to  go  that  distance 
in  a  couple  of  hours  in  a  comfortably  upholstered 
seat  in  a  nicely  warmed  and  brightly  lit  compart- 
ment. The  travellers  by  the  first  coach  no  doubt 
looked  back  upon  their  forefathers  who  went  by 
still  more  primitive  means,  in  much  the  same  pitying 
way  that  we  now  look  back  upon  them. 

There  is  a  more  striking  way  of  showing  the  rapid 
growth  of  the  railway  than  mere  figures.  The  writer's 
B  17 


HISTORICAL  AND  PROPHETIC 


grandfather  was  a  manufacturer  in  a  midland  town 
(now  a  great  railway  centre)  about  100  miles  from 
London,  and  his  periodical  business  visits  to  the 
capital  were  made  by  coach.  The  writer's  father 
used  to  tell  of  his  first  trip  on  the  railway,  when  the 
carriages  were  of  the  most  primitive  type,  little 
better  than  cattle  trucks  of  the  present  day  ;  indeed, 
they  were  worse  than  cattle  trucks  in  that  they  were 
open  to  the  sky. 

Again,  the  writer  remembers,  when  a  boy,  fre- 
quently meeting  the  gentleman  who  subsequently 
became  known  as  Sir  James  Alport,  the  man  who 
led  the  way  in  ministering  to  the  comfort  of  the 
passengers.  He  was  the  General  Manager  of  the 
Midland  Railway,  and  it  was  the  reforms  promoted 
by  him  which  have  led  to  the  pleasant  conditions  of 
travel  which  we  now  enjoy. 

He  it  was  who  introduced  the  practice  of  running 
third  class  carriages  on  all  trains  and  who  made  the 
third  class  carriages  comfortable. 

Thus  we  see  that  three  generations  is  sufficient 
to  cover  almost  the  entire  history  of  the  railway, 
and  one  is  enough  to  cover  the  era  of  improvement 
which  has  so  much  added  to  the  pleasure  of  a  journey 
from  the  point  of  view  of  the  ordinary  common  person 
who  goes  third  class. 

We  are  apt,  when  thinking  about  what  the  railways 
have  done  for  us,  to  forget  the  carriage  of  goods  ; 
we  think  about  the  matter  almost  entirely  in  terms 
of  passengers.  Yet  probably  the  ease  of  movement 
of  goods  which  the  railways  have  brought  about  has 
added  to  our  happiness  and  comfort  far  more  than 

18 


HISTORICAL  AND  PROPHETIC 

have  the  facilities  for  passenger  travel.  Before  the 
railway  came  each  district  must  have  depended  for 
its  food,  clothing  and  other  supplies  to  a  very  great 
extent  upon  its  immediate  neighbours. 

Take  the  cotton  of  which  our  shirts  are  made,  for 
an  example.  It  is  grown  probably  in  the  interior 
of  the  southern  part  of  the  United  States,  whence 
it  travels  by  train  to  the  nearest  sea-port.  After  a 
voyage  across  the  ocean  it  reaches  Liverpool,  whence 
it  goes  by  train  to  one  of  the  cotton-spinning  towns 
of  Lancashire.  Having  been  spun  and  woven  it 
travels  again  by  train  to  the  town  where  we  happen 
to  reside. 

After  making  all  allowance  for  the  boats  on  the 
Mississippi  River,  the  possibility  of  canal  carriage  and 
the  sea  voyage,  we  still  see  that  without  the  railway 
our  shirts  would,  at  least,  "  cost  us  more,"  even  if 
we  could  procure  them  at  all. 

Even  still  more  striking  is  the  case  of  the  grain 
which  forms  our  principal  food.  In  pre-railway 
days  the  people  of  Sussex,  for  example,  must  have 
had  to  live  almost  entirely  upon  Sussex  wheat,  and 
the  same  with  every  other  district.  Now  the  great 
wheat-growing  lands  of  the  United  States  and 
Canada  are  able  to  pour  their  produce  by  means  of 
the  railways  into  the  ships  at  the  ports,  and  after  a 
sea-voyage  it  is  again  distributed  by  rail  to  the 
populous  centres  for  consumption.  In  other  words, 
the  food  upon  which  we  depend  for  life  must  be  far 
more  plentiful  than  it  could  possibly  be  were  it 
not  for  the  railways.  Without  them,  those  vast 
areas  which  now  grow  wheat  for  export  would  be 

19 


HISTORICAL  AND  PROPHETIC 

untilled,  for  they  would  have  no  market  for  their 
product. 

The  old  method  of  transport  by  horsed  wagon 
could  not  possibly  deal  with  the  traffic  which  is  now 
handled  easily  by  rail. 

In  the  old  days,  the  roads  must  have  presented  a 
very  different  spectacle  from  what  they  do  to-day. 
There  must  have  been,  in  addition  to  the  coaches 
and  saddle  horses  which  have  since  been  displaced 
by  the  passenger  train,  long  trains  of  heavy  wagons 
and  pack-horses  doing  in  a  small  way  what  the  goods 
trains  now  do. 

Parcels  and  other  small  packages  were  sent  by 
the  coaches,  and  for  that  purpose  were  left  at  the 
various  inns,  whence  the  coaches  used  to  start  or 
where  they  used  to  call. 

This  has  led  to  a  rather  curious  survival  which  we 
may  still  notice  to-day.  When  the  railways  came 
on  the  scene  they  of  course  took  over  this  parcel 
traffic,  and  in  some  cases  they  took  over  the  inns 
also,  with  the  result  that  in  London  a  number  of 
modern  railway  depots  still  bear  the  old  picturesque 
names  of  the  inns  whose  place  they  have  taken. 
Thus  we  have,  or  at  all  events  had  until  recently, 
railway  depots  called  "  Castle  and  Falcon,"  "  Bull 
and  Mouth,"  "  Swan  with  two  Necks,"  "  Blossoms." 

Another  survival  is  the  use  of  the  words  "  Booking 
Office  "  for  the  place  where  we  buy  our  railway 
tickets.  It  arises  from  the  fact  that  when  a  man 
wanted  to  travel  by  coach  he  used  to  go  to  the  inn 
which  formed  the  coaching  "  station  "  and  arrange 
for  his  seat,  which  was  duly  entered  in  a  book.  In 

20 


HISTORICAL  AND  PROPHETIC 

fact,  he  booked  his  seat  upon  a  coach  just  as  one 
may  now  book  a  seat  in  a  theatre.  The  mere  selling 
of  a  ticket  cannot  really  be  called  "  booking,"  but 
we  still  use  the  old  term. 

In  the  early  days  there  were  many  people  who 
opposed  railways  from  mere  prejudice,  an  act  which 
their  successors  of  to-day  sorely  regret.  There  is, 
for  example,  a  town  in  Northamptonshire  which 
used  to  be  of  considerable  importance.  If  you  were 
to  visit  it  to-day  you  would  notice  by  the  size  of  its 
public  buildings  and  churches  that  it  was  evidently 
at  one  time  a  more  prosperous  place  than  it  is  now, 
and  the  explanation  is  that  when  a  certain  great 
railway  line  was  projected  the  people  of  this  town 
strongly  objected  to  it.  They  carried  their  objection 
so  far  that  the  promoters  of  the  line  were  forced  to 
divert  their  route,  and  instead  of  going  through  the 
town  they  went  through  a  village  four  miles  away. 
Now,  if  you  want  to  go  to  that  town  you  alight  at 
the  station  in  the  one-time  village,  now  a  large  and 
thriving  town,  and  wait  until  a  little  'bus  comes 
along  to  carry  you  to  the  other  town  which  languishes 
four  miles  away.  The  railway  has  "  made  "  the  village 
and  in  so  doing  has  drawn  a  large  amount  of  its 
prosperity  away  from  the  older  town. 

Many  suburbs,  too,  have  been  "  made  "  by  rail- 
ways. There  are  to  the  south-west  of  London  a 
number  of  what  used  to  be  little  isolated  hamlets 
lying  along  the  line  of  the  South- Western  Railway. 
This  enterprising  Company  had  the  wisdom  to  see 
that  these  were  nice  places  for  people  to  live  in,  so 
they  electrified  their  local  trains,  increased  im- 

21 


HISTORICAL  AND  PROPHETIC 

mensely  the  number  of  trains  and,  in  fact,  started  a 
fine  service  to  these  small  places.  The  result  has 
been  that  the  small  hamlets  have  quickly  grown 
into  populous  districts. 

This  sort  of  thing  has  given  rise  to  a  new  way  of 
teaching  geography.  The  modern  geography  text- 
book takes  as  its  basis  the  railways.  Along  them 
the  chief  towns  are  to  be  found,  for  indeed,  the 
whole  structure  of  a  country,  looked  at  as  a  place 
where  people  live,  is  built  up  upon  a  framework  of 
railways. 

But  there  is  now  a  strange  movement  of  traffic 
away  from  the  railways  and  back  to  the  roads, 
brought  about  by  the  success  of  the  mechanical 
road  vehicle  in  its  various  forms.  The  first  class 
railway  passenger  is  more  and  more  inclined  to  go 
in  his  own  motor,  the  third  class  man  is  tempted  by 
the  motor  omnibus  and  the  motor  char-a-banc, 
while  the  steam  wagon  and  the  motor  lorry  are 
successfully  handling  much  goods  traffic. 

In  this  connection  it  is  curious  to  notice  that  the 
road  locomotive  actually  preceded  the  railway  loco- 
motive. Richard  Trevithick  himself,  who  really 
preceded  Stephenson,  seems  to  have  made  a  quite 
successful  steam  wagon  which  worked  upon  the 
roads  in  Cornwall  in  the  very  early  days  of  the 
nineteenth  century.  It  was  probably  the  condition 
of  the  roads  of  those  days  which  led  to  the 
quick  development  of  the  railway,  but  retarded 
the  improvement  of  the  road  engine  for  many 
years. 

The  mention  of  the  name  of  Trevithick  brings  us 

22 


HISTORICAL  AND  PROPHETIC 

to  one  of  the  pathetic  incidents  of  railway  history. 
This  man,  who  was  undoubtedly  a  great  genius, 
worked  upon  the  idea  of  steam  transport  with  a 
very  considerable  amount  of  success.  One  of  his 
engines  was  at  work  at  Merthyr  before  that  of 
Stephenson  was  at  work  in  the  North.  He  had  success 
within  his  grasp,  and  with  just  a  little  more  per- 
sistency he  would  have  gone  down  in  history  as  the 
inventor  of  the  successful  steam  locomotive,  perhaps 
the  most  beneficent  invention  of  all  time. 

He  allowed  himself  to  be  discouraged,  however, 
while  the  man  of  stronger  character  pushed  on  in 
spite  of  failures,  until  at  last  he  was  rewarded  by 
victory  over  all  his  difficulties. 

Speaking  of  difficulties,  it  is  interesting  to  note 
that  one,  at  least,  of  the  obstacles  against  which  the 
early  pioneers  fought  turned  out  to  be  purely  imagi- 
nary. They  got  it  into  their  heads  that  a  smooth 
wheel  upon  a  smooth  rail  would  slip  rather  than 
haul  a  train  along.  They  therefore  expended  much 
time,  thought  and  expense,  in  the  early  trials,  on 
devising  a  suitable  rack  with  teeth,  alongside  the 
running  rails,  so  that  a  toothed  wheel  on  the  engine 
might  engage  with  it  and  so  propel  the  train  along. 
They  assumed  that  this  difficulty  existed  ;  when  at 
last  they  tried  it  they  found  that  the  rack  was  not 
necessary,  and  that  all  their  efforts  in  that  direction 
had  been  sheer  waste. 

Another  curious  feature  about  the  invention  of  the 
railway  is  the  strangely  odd  dimension  of  4  ft.  8  J  ins., 
which  is  the  most  usual  "  gauge  "  or  distance  between 
the  rails.  One  could  understand  it  being  4  ft.  6  ins. 

23 


HISTORICAL  AND  PROPHETIC 

or  5  ft.  or  1  metre — but  why  4  ft.  8J  ins.  ?    Why,  in 
particular,  that  odd  half-inch  ? 

The  answer  is  that  it  is  pure  accident.  The  old 
ways  along  which  horses  used  to  pull  carts  at  the 
colliery  where  George  Stephenson  worked  were  about 
that  distance  apart,  and  so  his  first  engines  came 
to  be  made  to  that  dimension,  and  as  soon  as  a  few 
had  been  so  made  it  became  a  matter  of  considerable 
difficulty  to  alter  it.  Had  it  been  totally  unsuitable 
it  would  no  doubt  have  been  changed,  but  it  was 
just  about  a  convenient  size,  and  the  result  is  that 
in  almost  all  parts  of  the  world  there  are  railways 
with  the  rails  that  odd  distance  apart. 

In  some  places  where  a  lighter  form  of  railway  is 
ample  for  the  needs  of  the  traffic  the  gauge  has  been 
made  a  metre.  In  some  very  light  lines  it  is  narrower 
still,  while  in  yet  other  parts  it  is  rather  wider,  but 
the  commonest  gauge,  by  far,  throughout  the  whole 
world  is  4  ft.  8|  ins. 

The  younger  of  the  two  famous  engineers,  by  name 
Brunei,  who  played  a  large  part  in  the  early  days 
of  the  Great  Western  Railway,  was  a  great  believer 
in  a  wider  gauge,  and  he  succeeded  in  making  the 
gauge  of  that  line  7  ft.,  but  it  was  found  to  be  so 
inconvenient  to  be  different  from  all  the  other  lines 
that  eventually  it  was  altered.  There  are  parts  of 
the  Great  Western  line  where  to-day  an  unusually 
wide  space  is  noticeable  between  the  pairs  of  rails, 
which  fact  is  due  to  the  reduction  in  the  gauge. 

So  much  for  the  past ;  now  a  word  as  to  the  future. 
As  has  already  been  remarked,  there  is  a  movement 
of  traffic  away  from  the  railway  and  back  to  the 

24 


HISTORICAL  AND  PROPHETIC 

road.  Will  it  continue  ?  May  we  anticipate  that 
railways  will  in  time  become  out  of  date  ? 

Unquestionably,  no  !  The  road  vehicle  will  never 
displace  the  railway,  but  it  will  help  it.  There  is 
and  always  will  be  a  need  for  means  to  bring  the 
traffic  to  the  railway.  A  railway  is  by  its  very  nature 
fixed.  It  may  throw  off  short  lines  and  sidings 
into  various  places  which  it  passes  closely,  but  the 
great  bulk  of  its  traffic  will  always  need  to  be  brought 
to  it.  Here  the  motor  vehicle  will  find  its  greatest  use. 

Just  before  the  road  motor  came  into  its  own 
there  was  a  great  movement  for  the  construction  of 
light  railways,  the  purpose  of  which  was  to  collect 
traffic  for  the  heavy  railways.  The  term  "  light  " 
railway  was  used  to  cover  a  line  of  usually  the 
standard  gauge,  but  in  all  other  respects  limited. 
The  speeds  were  limited,  for  instance,  so  that  many 
of  the  safeguards  rightly  insisted  upon  in  the  case  of 
ordinary  railways  might  be  dispensed  with.  They 
were  more  like  street  railways  or  tramways,  along 
which  goods  wagons  could  be  hauled  as  well  as 
occasional  passenger  trains.  Their  chief  use  was  to 
serve  farms  and  other  small  sources  of  traffic.  There 
are  many  such  lines  dotted  about  the  country,  but 
it  is  doubtful  if  many  more  will  be  constructed,  for 
the  motor  vehicle  has  since  shown  that  it  can  do  all 
that  was  expected  of  the  light  railway  and,  moreover, 
do  it  more  cheaply  and  conveniently. 

There  is  a  little  line  in  Staffordshire  where  the 
gauge  is  narrower  than  the  standard,  but  which  can, 
nevertheless,  be  traversed  by  standard  railway  trucks. 
This  is  done  by  the  provision  of  special  low  wagons, 

25 


HISTORICAL  AND  PROPHETIC 

whose  wheels  are  of  the  narrower  gauge  on  to  which 
the  standard  wagon  can  be  run  bodily.  This  principle 
may  in  time  be  adopted  to  facilitate  the  handling 
of  the  loads  as  they  are  brought  into  the  station  by 
the  motor  lorries,  the  whole  body  of  the  lorry,  with 
its  contents,  being  transferred  to  the  railway  truck 
without  any  intermediate  packing  or  unpacking.  In 
like  manner,  the  incoming  goods  may  arrive  already 
packed  in  receptacles  which  can  be  moved  bodily 
on  to  the  lorry.  An  enormous  saving  in  labour  will 
thus  be  effected. 

The  question  of  the  relative  cost  and  convenience 
of  road  and  rail  transport  will  probably  be  found  to 
depend  mainly  upon  distance.  If  a  man  wants  to 
send  coal  a  hundred  miles  it  will  almost  certainly 
pay  him  to  put  it  into  a  railway  truck  and  send  it 
by  rail.  If  he  wants  to  send  it  two  miles  a  motor 
lorry  will  probably  serve  him  best.  Other  things 
enter  into  the  matter,  of  course,  but  that  is  the  main 
thing,  and  the  result  of  it  will  be  almost  inevitably 
that  long  journeys  will  be  by  rail,  while  mechanically 
propelled  road  vehicles  will  do  the  short  journeys 
and  also  collect  and  deliver  the  goods  for  the  railways 
at  the  beginning  and  end  of  the  long  journeys.  The 
two  things  will  work  hand-in-hand. 

This  combination  will  benefit  all  parties.  The  long 
railway  journeys  are  the  ones  which  pay  the  best, 
so  that  the  greater  the  proportion  of  long  journeys 
the  better  will  it  be  for  the  railways. 

Another  thing  to  be  looked  for  in  the  railway 
world  will  be  simplification  in  working.  The  pro- 
vision of  costly  safeguards  against  accident  has  gone 

26 


HISTORICAL  AND  PROPHETIC 

too  far.  It  has  almost,  if  not  quite,  reached  the 
point  where  the  number  of  safeguards  constitutes  a 
danger.  Without  sacrificing,  then,  the  safety  of  the 
passengers,  it  may  be  possible  to  save  considerably 
on  the  sums  hitherto  spent  upon  safeguards. 

The  central  fact  of  the  matter  is  that  the  railways 
have  got  to  serve  the  public  more  economically  than 
they  have  been  doing.  Like  everyone  else  in  the 
world  they  will  have  to  do  their  share  of  saving  in 
order  to  make  up  for  the  losses  of  the  war,  and  the 
way  they  will  have  to  do  it  will  be  to  give  an  equally 
good  service  at  a  lower  cost. 

Should  any  reader  of  this  book  be  of  an  inventive 
turn  of  mind,  there  is  no  more  fruitful  field  for 
ingenuity  than  to  seek  out  ways  by  which  railways 
can  achieve  this  end. 


27 


M 


CHAPTER  II 
RAILWAY  PIONEERING 

OST  of  the  matter  in  this  book  relates  to 
railways  in  the  highly  developed,  thickly 
populated  parts  of  the  world  where  every 
inch  of  the  country  was  well  known  before  the  line 
was  laid,  and  where  the  possibility  of  "  the  un- 
expected "  was  confined  to  the  chance  of  striking 
an  underground  spring  in  a  tunnel. 

Very  different  is  the  work  of  constructing  and 
maintaining  a  line  away  in  the  wilds  where  the 
railway  surveyors  are  often  the  first  civilized  men  to 
set  foot  along  the  line  which  the  railway  will  shortly 
follow. 

To  illustrate  this  kind  of  work  we  may  well  take 
one  of  the  most  valuable  and  at  the  same  time  most 
wonderful  of  these  pioneer  lines,  the  Grand  Trunk 
Pacific,  of  Canada. 

As  everyone  knows,  Canada  has  been  the  young 
giant  of  the  past  few  decades.  No  country  in  the 
world  has  ever  grown  so  quickly,  for  perhaps  no  other 
country  has  such  a  valuable  combination  of  mineral 
resources,  fertility,  extent  and  climate.  Moreover,  it 
is  so  situated  that  it  makes  a  powerful  call  upon 
men  and  women  to  come  and  occupy  its  empty 
spaces  and  to  develop  its  wealth.  On  the  one  hand 

28 


RAILWAY  PIONEERING 

is  the  United  States,  actually  adjoining,  with  a  vast 
population  and  its  own  empty  spaces  nearing  complete 
occupation.  What  wonder  that  some  of  its  more 
restless  and  adventurous  spirits  should  drift  over  the 
border  to  the  new  country  !  Then  it  is  so  handy 
for  "  home,"  as  the  colonist  insists  on  calling  Great 
Britain.  A  man  who  emigrates  to  Australia  feels 
himself  cut  off,  probably  for  the  rest  of  his  life,  from 
his  kith  and  kin,  but  to  run  home  from  Canada  is 
little  more  than  a  week's  journey.  Small  wonder, 
then,  that  British  people  by  the  thousand  have  flocked 
out  to  this  new  land  of  promise. 

The  older,  eastern  parts  of  Canada  have,  of  course, 
had  their  railway  systems  for  years,  and  that  wonder- 
ful line,  the  Canadian  Pacific,  stretched  like  a  steel 
band  right  across  the  continent ;  but  there  still 
remained,  in  the  year  1900,  room  for  another  great 
main  line  across  from  east  to  west,  following  a  some- 
what different  route  and  tapping  fresh  areas. 

The  Grand  Trunk  Railway  was  already  in  existence, 
indeed  it  was  the  first  railway  in  the  colony,  but  its 
system  served  almost  exclusively  the  older  part  on 
the  east.  The  idea  of  its  extension  westward  came 
to  the  mind  of  Mr.  C.  M.  Hayes,  an  American  railway- 
man who  had  been  brought  in  to  rescue  the  Grand 
Trunk  from  a  poor  financial  position  into  which  it 
had  fallen. 

This  far-seeing  administrator  perceived  the  opening 
for  a  new  line  across  Canada  ;  he  perceived,  too, 
what  a  splendid  addition  it  would  be  to  the  country's 
wealth-earning  machinery,  and  so,  with  characteristic 
energy,  he  set  out  to  push  his  idea. 

29 


RAILWAY  PIONEERING 

It  was  so  goody  however,  that  he  found  no  great 
difficulty  in  carrying  his  scheme  through  ;  the 
Government  of  the  colony  and  financiers  in  London 
being  alike  ready  to  help.  Thus  it  came  about  that 
early  in  the  present  century  the  great  undertaking 
was  commenced  which  would  provide  a  complete 
new  route,  All- Canadian,  from  Halifax  in  Nova 
Scotia  on  the  Atlantic  to  a  new  port  at  Prince  Rupert 
on  the  Pacific.  Part  of  the  work  was  undertaken 
by  the  Canadian  Government  and  part  by  the  Grand 
Trunk  Pacific  Railway  Company,  the  arrangement 
being  that  the  part  constructed  by  the  Government 
should,  when  finished,  be  leased  to  the  Company 
for  a  term  of  fifty  years  on  certain  terms,  so  that  the 
whole  line  should  be  operated  by  the  Company  as 
a  single  system. 

Now  a  good  deal  of  the  country  through  which 
this  line  had  to  pass  was  practically  unknown. 
There  were  maps,  it  is  true,  which  had  been  made  by 
survey  parties  at  various  times  for  the  Government, 
but  these  were  found  to  be  so  faulty  and  incomplete 
that  the  railway  surveyors  quickly  abandoned  them 
altogether  and  made  a  completely  new  survey, 
itself  a  heavy  and  laborious  task. 

The  first  step  was  to  make  a  preliminary  recon- 
naissance. The  general  direction  of  the  route  had 
been  decided  upon  and  parties  were  sent  over  this 
route  to  have  a  preliminary  look  at  it,  so  to  speak. 
They  were  quite  small,  consisting  usually  of  a 
surveyor  and  one  assistant,  with  perhaps  a  few  men 
to  help  to  carry  things.  They  travelled  as  "  light  " 
as  possible,  their  only  apparatus  being  an  aneroid, 

30 


RAILWAY  PIONEERING 

with  which  to  measure  roughly  the  ups  and  downs 
of  the  route,  and  a  compass.  Distances  were  roughly 
estimated  or  paced  out. 

Not  only  had  they  to  follow  the  route  suggested, 
but  they  were  instructed  to  range  over  the  country 
fifty  to  one  hundred  miles  on  either  side  in  case  any 
better  route  should  be  available. 

The  country  through  which  they  passed  was 
largely  uninhabited,  except  by  a  few  Indians  and 
trappers.  Many  miles  of  it  was  virgin  forest  pene- 
trated sometimes  by  tiny  footpaths,  but  more  often 
by  no  track  of  any  sort.  On  the  contrary,  the  fallen 
trees  formed  in  many  places  obstacles  which  they 
could  only  pass  at  the  rate  of  a  few  yards  per  hour. 
The  storm  and  the  fire  fiend  had  played  tricks  with 
the  forest  giants  at  some  time  or  other  and  had 
piled  them  together  in  confused  masses. 

In  other  parts,  too,  they  encountered  swamps, 
through  which  progress  was  only  just  short  of  im- 
possible— swamps,  as  one  writer  has  put  it,  "  big 
enough  to  submerge  an  English  county  in." 

These  features  would  be  varied  by  rough  rocks 
with  surfaces  slippery  with  decaying  vegetation, 
while  rivers  broad  and  swift  would  confront  the 
traveller  with  startling  suddenness.  These  they  would 
have  to  get  across  as  best  they  could,  the  most 
usual  form  of  progress  being  by  means  of  a  raft 
roughly  fashioned  as  needed  from  logs  gathered  in 
the  vicinity. 

Travel  was  on  the  whole  easier  in  winter  than  in 
summer.  In  summer  the  ground  was  apt  to  be  wet 
and  soft,  but  on  the  other  hand,  although  winter 

31 


RAILWAY  PIONEERING 

with  its  frost  made  the  ground  firm  and  hard  it  also 
brought  the  blizzard  and  the  snowstorm,  the  snow- 
drift and  the  frost-bite.  Temperatures  ranging 
down  to  35  degrees  below  zero  bring  dangers  of  their 
own. 

Speaking  generally,  the  area  traversed  was  from 
300  to  400  miles  beyond  the  edge  of  civilization,  so 
that  each  little  party  was  completely  isolated,  and 
should  an  accident  have  happened  the  news  might 
have  taken  months  to  reach  their  fellow-men,  if, 
indeed,  it  ever  reached  them  at  all. 

After  this  preliminary  reconnaissance  had  been 
completed  a  more  definite  line  of  route  was  pro- 
visionally decided  upon,  and  then  parties  set  out 
upon  the  "  first  location  "  with  a  view  to  a  more 
definite  decision  still. 

These  parties  consisted  of  about  twenty  men  in 
each,  and  they  took  with  them  complete  surveying 
apparatus,  theodolites,  levels  and  the  like,  by  means 
of  which  they  made  accurate  plans  of  what  they 
considered  would  be  the  best  course  for  the  railway 
to  follow.  If  there  were  several  possible  alternatives 
they  surveyed  them  all,  sending  the  plans,  together 
with  a  report,  to  the  engineer-in-chief  for  con- 
sideration. 

These  reports  had  to  give  the  fullest  possible 
details  of  the  country,  particularly  the  levels  and 
gradients,  the  geological  formation,  notes  as  to  the 
facilities  for  the  construction  of  bridges,  in  fact  all 
manner  of  information  which  might  have  the  slightest 
bearing  upon  the  construction  of  the  line.  In 
addition  to  this  the  reports  were  required  to  include 

32 


RAILWAY  PIONEERING 

references  to  the  character  of  the  country  and  its 
possibilities  from  a  commercial  point  of  view,  for, 
of  course,  the  promoters  wanted  to  run  their  line 
so  as  to  tap  the  most  profitable  traffic. 

For  transport  they  were  provided  with  sleighs 
and  toboggans  and  any  other  form  of  transport 
suitable  to  the  area  in  which  they  were  working. 

After  one  party  had  been  over  the  ground  and 
had  reported  upon  a  location  another  party  did  the 
same  thing  in  order  to  check  the  first.  Sometimes 
even  a  third  went  over  it  so  as  to  arrive  at  a  third 
opinion. 

Even  then,  however,  the  matter  was  not  finally 
settled,  because  a  survey  party  went  ahead  of  the 
construction  people  in  case,  even  at  the  last  moment, 
an  improvement  of  some  sort  should  be  found  possible. 

When  fixed  upon  by  the  surveying  parties  the  line 
for  the  railway  was  indicated  by  a  row  of  stakes  100  ft. 
apart,  and  where  possible  a  rough  preliminary  clearing 
was  made  to  form  a  track  100  ft.  wide,  while  every 
1000  ft.  a  peg  was  put  in  with  the  altitude  marked 
on  it. 

The  support  and  provisioning  of  the  survey 
parties  was  in  itself  a  most  formidable  task,  yet  it 
was  one  upon  which  the  ultimate  success  of  the 
railway  largely  depended.  Just  think  for  a  moment. 
A  thousand  odd  men,  split  up  into  small  parties, 
spread  over  a  line  about  2000  miles  long,  most  of 
them  working  in  virgin  country,  amid  forests  and 
swamps,  in  rocky  defiles  and  on  rushing  rivers.  Yet 
being  men  they  had  to  be  fed  and  kept  in  health 
and  good  spirits. 

c  33 


RAILWAY  PIONEERING 

Much  use  was  made  of  Indians.  As  a  matter  of 
fact,  a  considerable  part  of  this  line  runs  through 
the  territory  reserved  for  the  Indians.  When  the 
Canadian  Pacific  line  was  made,  many  of  these 
people  were  induced  to  leave  the  line  of  that  railway 
and  settle  in  these  more  remote  parts,  the  idea  being 
that  they  would  never  need  to  be  disturbed  there. 
With  the  development  of  the  country  outrunning 
the  wildest  anticipations,  however,  the  time  came 
when  it  was  desirable  to  run  the  line  through  the 
new  Indian  reserve,  and  it  needed  much  diplomacy 
to  get  their  sanction.  This  was  ultimately  obtained, 
and  in  the  preliminary  surveys  particularly  the 
Indians,  with  their  intimate  local  knowledge,  their 
hardy  well-trained  frames  and  their  indifference  to 
hardship,  rendered  very  valuable  service. 

Another  class  of  men  who  were  found  to  be  of  the 
greatest  value  were  the  trappers  and  other  men  in 
the  employ  of  the  Hudson  Bay  Company.  Many  of 
these  men  had  spent  years  in  the  wilds,  had  re- 
markable local  knowledge  and  an  admirable  system 
of  intercommunication  between  the  isolated  posts, 
the  growth  of  many  years  of  experience. 

Still,  the  railway  engineers,  while  making  every 
use  of  the  Indians  and  trappers,  had  to  depend 
mainly  upon  their  own  efforts.  So  they  made  roads 
of  a  sort,  through  the  forest,  from  convenient  points, 
cutting  the  line  of  the  survey  at  intervals.  True, 
these  roads  were  only  a  few  feet  wide,  just  enough 
to  get  a  sledge  along,  but  they  served  as  the  lines 
of  supply.  At  the  ends  of  them  were  formed  depots 
or  "  caches  "  where  food  and  other  necessities  were 

34 


RAILWAY  PIONEERING 

stored,  and  from  these  depots  the  parties  drew  their 
supplies  as  they  needed  them. 

The  roads  were  supplemented  by  small  flat-bot- 
tomed steamers,  which  were  able  thus  to  use  some  of 
the  rivers,  while  other  parts  again  were  best  reached 
by  canoes. 

It  must  not  be  thought,  however,  that  these  were 
pleasure  trips  on  the  rivers.  On  the  contrary,  the 
canoe  men  often  had  the  roughest  experience* 
particularly  when  "  portage  "  was  necessary.  This 
operation  consists  in  unloading  the  canoe,  carrying 
the  cargo  over  or  around  some  obstacle,  then  doing 
the  same  with  the  canoe  itself,  which  is  finally 
re-launched  and  re-loaded.  Sometimes  this  may  be 
done  to  pass  some  rapids,  or  it  may  be  necessary  to 
leave  one  stream  and  change  on  to  another,  and  the 
men  may  have  to  carry  the  stuff  anything  from  a 
few  yards  to  a  mile.  Given  a  heavy  canoe,  with  a 
ton  of  stuff  on  board  and  a  crew  of  two  men,  it  is 
easy  to  realize  that  the  work  is  arduous. 

In  winter,  with  the  ground  hardened  by  frost, 
dog  sleighs  were  largely  used. 

At  certain  strategic  points  doctors  were  stationed. 
The  clean  fresh  air  and  hard  life  on  the  whole  made 
cases  of  illness  few  and  far  between,  but,  of  course, 
there  were  some  cases  and  accidental  injuries  were 
unavoidable. 

In  spite  of  all  this  care  and  forethought,  however, 
things  went  wrong  occasionally.  In  one  case,  at 
least,  a  surveying  party  were  nearly  lost  through 
starvation.  They  strayed  too  far  away  from  their 
depot,  probably  led  on  by  the  interest  of  the  work 

35 


RAILWAY  PIONEERING 

and  misled  by  a  wrong  calculation  as  to  the  amount 
of  food  which  they  had  with  them.  Realizing,  at 
last,  their  danger,  they  retraced  their  steps  through 
a  snowstorm,  but  several  days'  march  brought  them 
no  succour  until,  fagged  out  and  longing  for  sleep, 
they  heard  voices  in  the  forest.  It  is  to  be  regretted 
that  the  voices  were  swearing,  as  it  turned  out,  at  the 
dogs  which  were  drawing  a  sledge-full  of  supplies. 
Thus  help  came  in  the  nick  of  time  and  the  whole 
party  were  saved,  but  it  was  a  narrow  escape. 

Another  danger  which  was  always  present  during 
this  work  was  the  bush  fires  which  are  so  prevalent 
in  those  regions.  If  once  a  fire  gets  going  when  the 
wood  is  dry,  it  spreads  with  astounding  rapidity 
and  may  overtake  or  encircle  an  unfortunate  party. 
Little  can  be  done,  unless  large  forces  of  men  are  at 
hand,  to  stop  the  spread  of  the  fires.  The  only  thing 
to  do  is  to  keep  a  sharp  look  out,  and  on  perceiving 
danger  to  flee. 

In  this  connection  it  may  be  interesting  to  remark 
that  the  Canadian  Government  are  hoping  to  evolve 
a  method  of  fighting  these  fires  from  the  air.  Aero- 
planes patrolling  the  forests  can  detect  the  fires  at 
great  distances,  and  it  is  hoped  that  by  dropping 
suitable  chemical  bombs  they  may  be  able  to  ex- 
tinguish them, 

It  was  during  the  operations  of  these  survey  parties 
that  many  valuable  discoveries  were  made.  Minerals 
of  one  sort  and  another  were  found,  here  and  there, 
but  the  greatest  discovery  of  all  was  that  underlying 
a  large  extent  of  forest  was  what  came  to  be  called 
the  "  clay  belt."  This  meant  that  many  thousands 

36 


RAILWAY  PIONEERING 

of  square  miles  of  land  which  had  been  thought  to 
be  only  fit  for  growing  wild  timber  was  found  to  be 
capable  of  cultivation.  Indeed,  its  nature  was  such 
that  it  is  not  only  capable  of  growing  valuable  crops, 
but  is  particularly  fertile. 

This  discovery  meant  an  enormous  addition  not 
only  to  the  future  traffic  of  the  railway,  but  to  the 
wealth  of  the  country. 

What  has  been  said  so  far  relates  mainly  to  the 
part  of  the  line  which  traverses  the  fairly  level 
country.  In  order  to  reach  the  Pacific  Coast  it  was 
necessary,  somehow,  to  penetrate  the  vast  rocky 
barrier  known  as  the  Rocky  Mountains. 

The  promoters  had  made  up  their  minds  that  by 
hook  or  by  crook  they  would  find  a  way  through 
rather  than  over  this  mighty  range.  The  Canadian 
Pacific  line  and  also  the  United  States  lines  which 
run  from  east  to  west  had  had  to  climb,  more  or  less, 
over  the  range.  Of  course,  they  took  advantage  of 
the  passes,  the  lower  parts  between  the  peaks ;  but 
do  what  they  could,  they  had  a  stiff  climb  on  both 
sides  of  the  range. 

Now  even  a  slight  incline  is  an  abomination  on  a 
railway.  It  involves  huge  expense.  Engines  have 
to  be  specially  big  and  heavy  just  because  of  a  few 
miles  of  steep  gradient,  extra  engines  have  to  be 
employed  and  the  cost  for  fuel  is  enormous.  On 
this  line  it  was  decided  that  a  way  should  be  found 
not  steeper  than  21  ft.  rise  per  mile.  That  seems  a 
very  easy  gradient,  in  all  conscience,  with  which 
to  scale  the  snow-capped  Rocky  Mountains,  and 
one  wonders  at  the  optimism  of  the  men  who  set 

37 


RAILWAY  PIONEERING 

themselves  the  apparently  impossible  task  of  finding 
such  a  route.  But  they  did  it. 

Over  10,000  square  miles  of  country  was  closely 
examined  to  find  the  best  route.  Forty  passes 
were  investigated  and  surveyed.  Then  the  forty 
were  reduced  to  six  ;  then  to  three,  until  the  final 
choice  fell  upon  the  Yellowhead  Pass,  through  which 
the  line  passes  without  exceeding  the  very  low 
limit  of  gradient  which  has  been  mentioned. 

After  this  description  of  the  preliminary  work,  we 
may  well  devote  a  further  chapter  to  the  work  of 
construction  to  which  it  led  up.  (See  chap,  xxi.) 


CHAPTER  III 
WHERE  THE  LOCOMOTIVES  ARE  MADE 

IN  this  chapter  we  will  take  a  stroll  through 
the  locomotive  works  of  one  of  the  leading 
British  railways.  It  is  an  account  of  an  actual 
tour  of  inspection  made  for  the  express  purpose  of 
leading  our  readers  in  thought  through  the  same 
interesting  experience. 

We  enter  a  large  door  leading  into  the  "  Machine 
Shop,"  the  large  building  in  which  are  the  bulk  of 
the  "  machine  tools  "  by  which  the  various  parts 
of  the  engines  are  fashioned  before  they  pass  to  the 
Erecting  Shop  to  be  put  together.  It  is  a  large 
single  story  building,  a  good  deal  of  glass  making 
it  light  and  cheerful.  The  roof  is  supported  on  rows 
of  columns,  the  upper  parts  of  which  also  serve  to 
carry  the  overhead  shafting  and  pulleys  by  which 
the  power  is  transmitted  from  the  electric  motors 
dotted  about  the  shop  to  the  machines. 

The  spaces  between  the  rows  of  columns  form 
aisles  and  the  machines  are  set  out  in  long  rows, 
generally  speaking,  two  rows  in  each  aisle  with  a 
passage  way  between  the  two.  Thus  the  floor  is 
well  covered  with  machinery,  while  above,  just 
beneath  the  roof,  is  a  maze  of  moving  belts. 

The  first  machines  encountered  are  what  are 

39 


WHERE  THE  LOCOMOTIVES  ARE  MADE 

termed  "  automatics,"  for  they  go  on  making  certain 
articles  over  and  over  again  without  any  attention, 
or  to  be  more  precise  with  only  occasional  attention. 

The  articles  made  by  them  are  such  things  as 
bolts  and  pins,  of  which  every  engine  contains  a 
large  number  all  alike.  It  is  no  use  employing  an 
automatic  lathe  for  anything  unless  you  want 
thousands  just  the  same,  for  the  original  "  setting 
up  "  of  the  machine  takes  a  lot  of  time  and  is  not 
worth  doing  for  only  a  few. 

Let  us  take  a  closer  view  of  these  mechanical 
wonders.  As  most  people  know,  a  lathe  is  a  machine 
in  which  a  piece  of  metal  is  turned  round  in  order 
that  a  steel  tool  may  be  moved  in  contact  with  it  in 
such  a  manner  as  to  take  a  cut  off  it.  In  ordinary 
lathes  the  tool  is  held  in  a  sort  of  carriage  capable 
of  moving  in  all  directions  at  the  will  of  the  operator, 
and  the  work  is  then  largely  done  "  free-hand,"  the 
tool  being  altogether  and  entirely  under  the  personal 
guidance  of  the  workman.  Such  machines  are  em- 
ployed in  all  engineering  works  and  are  absolutely 
essential  for  all  general  work.  They  are  the  most 
numerous  form  of  machine  tool  in  all  engineering 
works  and  are  to  be  seen  in  all  sorts  and  shapes, 
adapted  for  different  classes  of  work.  Some  are 
made  specially  for  turning  long  but  comparatively 
thin  articles,  others  are  for  turning  short  things  of 
large  diameter,  some  are  for  small  things,  some  for 
large,  some  have  a  screw  which  propels  the  carriage 
along  in  such  a  manner  that  it  can  cut  accurate 
screw  threads,  others  lack  this  device,  and  so  on. 

They  are  all  alike,  however,  in  that  they  possess. 

40 


WHERE  THE  LOCOMOTIVES  ARE  MADE 

a  "  bed  "  and  a  "  headstock."  The  former  may  be 
described  as  a  long,  low  bench,  made  of  iron,  the 
upper  surface  and  the  edges  of  which  are  planed 
quite  flat  and  straight. 

The  headstock  sits  upon  the  bed  at  the  left-hand 
end.  It  consists  of  a  spindle,  carried  in  bearings, 
so  that  it  can  turn  round  freely  and  truly,  pulleys 
for  driving  it  round  and  a  screwed  end  on  to  which 
can  be  placed  some  device  for  holding  the  article  to 
be  turned.  The  spindle  is,  of  course,  horizontal  and 
parallel  with  the  centre-line  of  the  bed.  Special 
appliances  are  often  made,  to  screw  on  to  the  end  of 
the  spindle,  to  facilitate  the  holding  of  certain 
objects,  but  for  general  purposes  there  are  always 
two.  The  first  of  these  is  called  a  "  face-plate  "  and 
consists  of  a  disc  of  iron,  as  large  as  the  machine  will 
accommodate,  with  a  lot  of  holes  and  slots  in  it 
through  which  bolts  can  be  passed  for  the  purpose 
of  fixing  the  work  upon  it. 

The  other  thing  is  called  a  "  chuck,"  why,  the 
present  writer  has  no  notion.  It  certainly  does  not 
"  chuck  "  things  about,  for  its  duty  is  to  do  the  exact 
opposite,  to  hold  them  firmly.  A  round  drum-shaped 
object,  it  has  three  or  four  jaws  which,  by  the  opera- 
tion of  a  key,  can  be  made  to  advance  or  recede 
along  radial  lines  to  and  from  the  centre.  When  a 
workman  is  instructed,  therefore,  to  "  chuck "  a 
certain  thing  he  does  not  throw  it  or  leave  it  alone, 
but  having  drawn  the  jaws  back  sufficiently  far,  he 
inserts  the  object  between  them  and  then  moves 
them  towards  it  until  they  grip  it  securely.  In 
some  cases  all  the  jaws  move  together,  so  that 

41 


WHERE  THE  LOCOMOTIVES  ARE  MADE 

anything  round,  if  gripped  by  them,  must  be  central 
with  the  spindle. 

For  turning  long  objects  a  further  support  is 
required,  and  that  is  furnished  by  the  "  tailstock," 
a  strong  support  of  iron  carrying  a  steel  point  or 
"  centre."  The  whole  thing  can  be  moved  at  will 
along  the  bed  and  fixed  at  any  point,  and  the  "  centre  " 
itself  can  also  be  moved  a  few  inches  by  means  of  a 
screw  and  a  hand-wheel. 

Thus,  a  long  object  is  fixed  by  some  suitable  means 
in  the  headstock,  while  the  tailstock  is  brought  up 
until  the  back  "  centre  "  just  fits  nicely  in  a  little 
dimple  made  for  the  purpose  in  the  right-hand  end 
of  the  object.  Thus,  while  supported  at  its  outer 
end  the  object  is  still  free  to  move. 

When  a  number  of  small  articles  are  required  all 
alike  a  semi-automatic  lathe  comes  in  useful.  Of 
these  there  are  a  number  to  be  seen  as  we  pass  along 
on  our  journey.  They  have  headstocks  and  beds, 
very  much  like  the  general-purpose  lathes  which 
have  just  been  described,  but  in  addition  they  have  a 
strange-looking  cylindrical  object  mounted  upon  the 
carriage  instead  of  the  simple  arrangement  for 
holding  the  tools  which  we  have  just  been  looking  at. 

This  curious  object  is  called  a  "  capstan,"  or 
sometimes  a  "  turret,"  and  if  you  look  carefully  at 
it  you  will  notice  there  are  five  or  six  holes  in  it  set 
all  round  it  at  regular  intervals. 

Each  of  those  holes  is  intended  to  hold  a  tool,  so 
that  the  tools  for  five  or  six  operations  can  be  held 
at  the  same  time.  Moreover,  the  capstan  turns 
round  on  the  movement  of  a  certain  handle  in  such 

42 


WHERE  THE  LOCOMOTIVES  ARE  MADE 

a  manner  as  to  bring  each  tool  into  operation  in 
succession. 

Just  look  at  the  saving  of  time  which  that  means  ! 
In  the  ordinary  lathe  the  man  carries  out  one  opera- 
tion, then,  in  all  probability,  he  has  to  take  out  the 
tool,  get  another  one  and  fix  it  in  its  place.  Quite 
a  small  object  may  call  for  four  or  five  operations, 
each  needing  a  different  tool  or  the  tool  in  a  different 
position,  and  in  an  ordinary  lathe  the  workman 
would  spend  the  greater  part  of  his  time,  were  he 
making  a  number  of  small  things,  in  changing  his 
tools. 

If  he  has  a  capstan  lathe,  however,  each  tool 
comes  into  position  as  needed  at  the  mere  motion  of 
a  handle.  Not  only  so,  in  the  great  majority  of  such 
machines  the  material  from  which  the  article  is  to 
be  made,  generally  a  rod  or  round  bar,  is  automatically 
moved  into  position  and  then  gripped,  again  by 
simply  two  motions  of  a  handle. 

Let  us  go  a  little  further  on  and  watch  a  man 
making  some  small  bolts  in  a  machine  of  this  kind. 
The  material  is  a  bar  of  steel,  not  round,  but  hexagon, 
the  shape  of  the  heads  on  the  bolts.  He  has  just 
finished  one,  so  he  pulls  a  lever  and  the  bar,  which 
passes  through  a  hole  right  down  the  centre  of  the 
spindle,  moves  forward  until  just  enough  projects 
from  the  chuck  to  enable  the  next  bolt  to  be  made. 
Another  movement  of  the  handle  and  the  bar  is 
gripped  correctly.  A  movement  of  another  handle 
and  the  capstan  advances,  bringing  with  it  a  tool 
which  takes  a  deep  cut  off  the  metal,  bringing  it  to 
somewhere  near  the  right  size.  The  next  movement 

43 


WHERE  THE  LOCOMOTIVES  ARE  MADE 

of  the  handle  causes  the  capstan  to  retire,  and  as 
it  does  so  it  turns  round  just  enough  to  bring  the 
next  tool  into  operation,  after  which  it  comes  up  to 
its  work  once  more  and  takes  another  cut,  this  time 
making  it  just  the  right  size.  Another  motion  and 
a  third  tool  comes  into  play,  this  time  to  make  the 
thread.  And  so  it  goes  on  until  the  thing  is  finished, 
when  a  tool  comes  across,  cuts  off  the  finished  bolt 
and  leaves  the  end  of  the  bar  ready  to  be  brought 
forward  for  another  one. 

In  the  semi-automatic  lathe  these  things  are  all 
done  by  a  man  working  a  handle  or  handles  to  and 
fro.  The  man  does  the  same  succession  of  things 
over  and  over  again  like  a  machine,  so  that  it  is 
quite  a  natural  step  to  make  the  machine  itself 
pull  the  handles,  and  when  we  do  that  we  arrive  at 
the  fully  automatic  lathe  such  as  we  see  in  these 
works. 

In  place  of  the  man  there  is  a  series  of  drums 
underneath  the  machine  with  slanting  strips  fixed 
upon  them,  so  that  as  they  turn  they  occasionally 
encounter  the  end  of  a  lever  and  push  it  to  one  side. 
The  fixing  of  these  strips,  or  "  cams  "  as  they  are 
called,  is  a  matter  requiring  both  patience  and  skill 
if  they  are  to  do  their  duties  correctly,  because,  as 
is  quite  obvious,  the  success  of  the  whole  thing 
depends  upon  each  one  coming  into  operation  at 
precisely  the  right  moment. 

Thus,  as  we  watch  the  machine  at  work  we  notice 
one  of  these  cams  coming  slowly  round  ;  presently 
it  touches  the  end  of  a  rod,  slowly  the  rod  is  pushed 
over  and  a  new  operation  commences  ;  a  moment 

44 


WHERE  THE  LOCOMOTIVES  ARE  MADE 

later  another  cam  moves  another  rod  and  a  further 
operation  takes  place.  And  so  the  machine  goes  on 
until  the  bar  which  forms  its  material  has  been  all 
used  up.  One  skilled  man  can  set  up  a  number  of 
these  machines  and  it  is  sufficient  if  quite  an  un- 
skilled person  just  keeps  an  eye  upon  a  number  of  them. 

But  we  must  get  on  beyond  the  lathes,  of  which 
we  pass  a  large  number  of  all  sorts.  The  next  thing 
we  see  is  a  planing  machine.  You  know  those  long, 
flat  rods,  "  side-rods  "  they  are  called,  which  connect 
the  wheels  of  a  locomotive  together.  When  two 
boys  want,  in  play,  to  imitate  an  engine,  they  often 
stand  one  behind  the  other,  each  hand  grasping  the 
end  of  a  stick,  one  stick  on  each  side  of  them.  Then 
as  they  run  along  making  a  puffing  noise  they  make 
their  hands  go  round  like  the  cranks  on  the  sides  of 
the  engine.  The  sticks  in  that  case  represent  the 
side-rods. 

The  operation  which  we  are  now  looking  at  is 
planing  some  rough  bars  of  iron  or  steel  to  make 
them  flat  and  straight  so  that  they  will  do  to  form 
side -rods.  Planing  metal  is  not  quite  like  planing 
wood,  a  much  better  known  operation,  because  even 
the  most  powerful  machine  can  only  take  off  a  narrow 
strip  at  a  time,  instead  of  the  broad  shaving  which 
we  take  off  wood.  Otherwise,  however,  the  work 
is  just  the  same.  In  the  planing  machine  there  is  a 
strong,  heavy  table  of  iron,  flat  upon  its  upper 
surface  except  for  a  number  of  slots,  shaped  like  a 
letter  T  upside  down,  into  which  bolts  can  be  slipped 
for  the  purpose  of  holding  down  the  work  being 
planed. 

45 


WHERE  THE  LOCOMOTIVES  ARE  MADE 

The  table  is  so  arranged  that  it  can  slide  to  and 
fro  upon  long  guides  formed  in  the  base  of  the 
machine.  Under  the  table  are  wheels  and  gear  by 
which  the  table  can  be  propelled,  while  at  the  side 
is  a  trigger-like  arrangement  by  which  the  direction 
can  be  changed.  Look  at  it  now,  as  the  table  is 
coming  towards  us.  Suddenly  a  projection  upon  the 
side  of  the  table  works  the  "  trigger  "  and  the  table 
stops,  but  only  for  a  moment,  for  it  quickly  starts 
to  return  whence  it  came.  But  watch  it  still. 
Presently  another  projection  trips  the  trigger  once 
more  and  once  again  the  table  comes  forward. 
Thus  as  long  as  the  machine  is  working,  without  any 
attention  from  the  attendant,  the  table  keeps  moving 
to  and  fro.  Moreover,  by  adjusting  the  position  of 
the  projections  upon  the  side  of  the  table  the  workman 
can  make  the  length  of  the  stroke  what  he  will. 

Now  let  us  turn  our  attention  to  the  bridge,  as  we 
might  call  it,  which  spans  the  table. 

Springing  up  from  the  base  of  the  machine,  one 
on  either  side  of  the  table,  are  two  strong  pillars, 
while  between  them  there  stretches  a  strong  iron 
beam,  generally  spoken  of  as  the  "  cross-rail."  It 
is  these  which  form  the  "  bridge-like  "  object,  and 
their  purpose  is  to  carry  the  tool,  which  takes  a 
cut  off  the  object  as  it  slides  beneath.  The  carpenter 
moves  his  plane  over  the  wood,  in  this  machine  the 
work  moves  beneath  a  stationary  tool. 

The  tool  is  actually  fixed  in  what  is  termed  the 
"  tool-box,"  which  is  carried  upon  the  cross-rail. 
It  can  slide  along  the  cross-rail,  propelled  by  a  screw, 
and  at  every  backward  journey  of  the  table  another 

46 


WHERE  THE  LOCOMOTIVES  ARE  MADE 

trigger-like  arrangement  is  set  in  motion,  giving  the 
screw  a  slight  turn,  so  moving  the  tool-box  and  tool 
a  little  way  along  the  cross -rail.  Thus  the  tool 
makes  cut  after  cut,  each  one  straight  and  parallel 
to  the  last  one,  and  so  the  whole  surface  is  covered 
with  parallel  cuts  until  it  is  quite  smooth.  If  it 
only  needs  to  be  generally  flat  the  cuts  are  fairly 
coarse,  but  if  a  very  smooth  finish  is  required  they 
are  fine  and  close. 

The  cross-rail  itself  can  be  raised  and  lowered  by 
means  of  screws  operated  by  a  hand-wheel,  and 
there  is  another  screw  still  in  the  tool-box,  by  which 
slight  vertical  adjustments  can  be  made. 

Thus  we  see  how  the  side-rods  are  made  flat, 
straight  and  smooth.  To  save  time  on  the  part  of 
the  workman  a  number  of  them  are  set  upon  the 
table  side  by  side  and  the  machine  planes  right 
across  the  lot. 

Then,  as  you  will  remember,  there  is  a  hole  in 
each  end  of  the  rod,  where  the  pin  goes  which  projects 
from  the  side  of  the  wheel  of  the  engine.  It  is  very 
necessary  that  those  two  holes  should  be  precisely 
the  correct  distance  apart.  The  next  machine  that 
we  come  to  ensures  this.  It  is  a  special  form  of 
drilling  machine  for  this  work.  The  rod  is  fixed  in 
place  by  being  bolted  against  a  flat  surface  provided 
for  the  purpose,  and  then  two  spindles  commence 
to  rotate.  Each  of  these  spindles  carries  a  tool  which 
slowly  advances  until  it  has  passed  right  through  the 
bar  and  has  cut  out  a  nice  round,  smooth  hole. 
Both  spindles  work  at  the  same  time,  and  having 
once  been  fixed  at  the  correct  distance  apart  any 

47 


WHERE  THE  LOCOMOTIVES  ARE  MADE 

number  of  rods  can  be  drilled  without  any  risk  of 
the  holes  being  other  than  the  right  distance  apart 
too.  Of  course,  it  would  be  possible  to  drill  each 
end  separately,  but  then  the  workman  would  have 
to  be  exceedingly  careful  in  measuring  the  positions 
for  the  holes,  and  if  he  were  to  make  a  mistake  the 
whole  rod  with  all  the  work  already  put  upon  it 
would  be  wasted. 

Thus  the  special  machine  with  two  spindles  saves 
a  lot  of  time,  a  very  important  point  in  all  manu- 
facturing work.  And  speaking  of  saving  time,  I 
wonder  if  you  noticed  just  now  when  looking  at  the 
planing  machine  that  as  it  came  forward,  taking  a 
shaving  off  the  bars,  it  moved  fairly  slowly,  but  as 
soon  as  it  reversed  it  seemed  to  hurry  up,  doing  the 
return  stroke,  when  no  work  was  being  done,  in  less 
than  half  the  time.  That  again  is  an  instance  of  the 
saving  of  time  and  therefore  cost. 

But  what  is  this  curious  thing  ?  It  looks  like  a 
box  of  a  rather  strange  shape  of  a  roughish  grey 
metal.  Through  it  are  two  large  holes.  It  is  a 
casting  for  one  of  the  cylinders  of  an  engine.  We 
shall  see  castings  being  made  presently,  in  the 
foundry,  but  here  it  is  being  bored,  for  those  two 
large  holes  are  perhaps  the  most  important  things 
in  the  whole  engine.  One  is  the  cylinder  where  the 
steam  pushes  against  the  piston,  and  by  doing  so 
moves  the  train,  while  the  other  is  where  the  valve 
works  which  sends  the  steam  first  into  one  end  arid 
then  into  the  other,  at  the  same  time  liberating  the 
steam  which  has  done  its  work. 

Those  holes  have  to  be  bored  out  very  truly  and 

48 


WHERE  THE  LOCOMOTIVES  ARE  MADE 

very  accurately,  and  here  again,  the  two  must  be  a 
precise  distance  apart.  The  casting  is,  therefore, 
fixed  in  a  special  machine  with  two  spindles,  one  of 
which  bores  out  each  hole. 

And  now  we  may  notice  that  we  are  getting  to  a 
part  of  the  shop  where  heavier  work  is  done,  for  the 
roof  is  higher  and  high  up  overhead  there  is  an 
electric  travelling  crane,  the  duty  of  which  is  to  lift 
about  the  shop  any  heavy  parts  which  may  need  to 
be  handled.  Two  run-ways,  composed  of  strong 
girders,  run  along  each  side  of  this  higher  portion, 
while  spanning  from  one  to  the  other  is  a  pair  of 
steel  girders  forming,  as  it  were,  a  bridge  across  the 
shop,  the  ends  of  the  bridge  being  supported  upon 
carriages  which  run  on  rails  upon  the  top  of  the  run- 
ways, so  that  the  whole  thing  can  run  up  and  down 
the  whole  length  of  the  building.  Further,  upon  the 
bridge,  is  a  trolley,  the  wheels  of  which  run  upon 
rails  upon  the  bridge,  and  upon  it  are  the  motors 
and  lifting  gear,  also  the  cabin  for  the  driver. 

Since,  then,  the  bridge  can  run  from  end  to  end 
of  the  shop  and  the  trolley  can  run  from  side  to  side 
upon  the  bridge,  it  follows  that  the  trolley  can  place 
itself  over  every  part  of  the  shop  (that  is,  of  course, 
the  higher  portion)  and  lift  anything  from  any  part, 
carry  it  along  and  deposit  it  upon  any  other  part. 
The  whole  thing  is  worked  by  electricity  and  can 
be  perfectly  controlled  by  the  man  in  the  cabin. 

We  must  not  spend  too  much  time  in  this  shop, 

but  there  are  several  things  we  ought  to  note  as  we 

pass  on.     One  is  a  curious  form  of  lathe,  called  a 

vertical  boring  mill.     It  is  just  like  a  lathe,  except 

D  49 


WHERE  THE  LOCOMOTIVES  ARE  MADE 

that  its  spindle  is  vertical,  so  that  its  face-plate 
forms  a  round  table.  Its  special  virtue  is  that  it  is 
so  much  easier  to  fix  an  object  down  upon  a  horizontal 
surface  than  upon  a  vertical  one.  You  would  find 
it  easier,  for  instance,  to  fix  an  object  weighing  half 
a  hundredweight  upon  a  table  than  you  would  upon 
a  wall.  Being  easier  it  can  be  done  more  quickly, 
and  so  time  is  saved. 

Another  machine  is  called  a  slotting  machine. 
Its  purpose  is  to  plane  small  articles,  but  it  differs 
from  a  planing  machine  in  that  the  work  is  fixed 
while  the  tool  goes  up  and  down.  It  is  more  often 
called  upon  to  plane  grooves  and  slots  in  an  article 
than  to  plane  a  smooth,  flat  surface,  whence  we  see 
why  one  machine  is  called  a  planer,  but  the  other  a 
slotter. 

These  are  not,  of  course,  all  the  tools  in  the  shop 
by  any  means,  but  only  just  the  more  prominent 
ones. 

As  we  step  out  of  the  door  on  our  way  to  the  next 
place  of  interest  we  are  startled  by  a  succession  of 
deep  thuds  accompanied  by  a  distinctly  felt  vibration 
of  the  floor,  which,  by  the  way,  is  here  the  solid 
earth.  That  is  no  cause  for  alarm,  however,  for  it 
simply  betokens  our  approach  to  the  large  forge 
where  the  steam  hammers  are  at  work. 

Have  you  ever  watched — I  expect  you  have — a 
workman  in  the  street  standing  with  his  legs  well 
apart  pounding  away  at  the  paving  between  his  feet 
with  a  heavy  rammer  ?  A  steam  hammer  is  simply 
that  man  made  strong. 

It  consists  of  a  powerful  iron  cylinder  supported 

50 


WHERE  THE  LOCOMOTIVES  ARE  MADE 

upon  two  strong  legs  set  well  apart.  .  Inside  the 
cylinder  is  a  piston  just  like  that  of  any  other  steam 
engine.  The  cylinder  is  so  placed  that  the  piston 
goes  up  and  down,  and  the  piston  rod  is  very  stout 
and  strong.  To  the  lower  end  of  the  piston  rod  is 
attached  the  "  head "  of  the  hammer,  which  may 
weigh  several  tons. 

The  inlet  of  steam  into  the  cylinder  is  controlled 
by  a  handle  which,  as  we  look,  is  in  the  grip  of  the 
hammer-man.  A  slight  movement  of  his  hand  and 
up  goes  the  heavy  hammer-head,  for  he  has  let  the 
steam  in  under  the  piston.  There  for  a  moment  he 
holds  it  while  his  mates  adjust  the  lump  of  hot  iron 
upon  the  anvil  which  stands  between  the  "  feet  "  of 
the  machine.  When  all  is  ready  there  is  just  a 
flick  of  the  wrist  and  down  comes  the  hammer, 
and  the  great  lump  of  iron  squashes  as  if  it  were 
putty. 

It  is  most  fascinating  to  watch,  for  in  the  hands 
of  a  skilled  operator  the  hammer  is  almost  human. 
He  seems  to  be  able  to  "  play  upon  it  "  like  an 
instrument  and  to  make  it  do  anything,  from  gentle 
taps,  almost  tender  in  their  softness,  to  hard,  vicious 
thumps  into  which  the  machine  seems  to  put  all 
its  force. 

It  is  a  draw-hook  which  they  happen  to  be  making  ; 
one  of  those  strong  hooks  by  which  an  engine  is 
coupled  to  its  train.  The  heavy  bar  of  iron,  soft 
from  the  heat  of  the  furnace  whence  it  has  just  been 
drawn,  changes  its  shape  as  we  watch  almost  as  if 
the  workmen  were  wizards  rather  than  ordinary 
human  beings,  and  it  is  all  due  to  the  wonderful 

Si 


WHERE  THE  LOCOMOTIVES  ARE  MADE 

power  and  docility  of  these  great  machines.  There 
are  several  other  ones  at  work,  too,  but  we  have 
not  time  to  stay. 

In  the  next  shop  we  visit  they  are  making  what 
are  termed  "  drop-forgings,"  small  parts  made  of 
wrought  iron,  the  shape  of  which  is  against  their 
being  turned  out  of  a  bar.  The  hammers  used  for 
this  are  quite  different  from  the  steam  hammers 
which  we  have  just  left.  The  "  head  "  slides  up  and 
down  between  guides,  and  the  mechanism  is  so 
arranged  that  it  is  lifted  up  several  feet  and  then 
allowed  to  drop  of  its  own  weight.  Hence  they  are 
called  "  drop-hammers  "  and  the  forgings  made  by 
their  aid  are  "  drop-forgings." 

A  sort  of  sandwich  is  made  consisting  of  a  piece  of 
white-hot  iron  and  two  pieces  of  steel.  The  pieces 
of  steel  are  in  reality  dies  with  depressions  cut  in 
them  of  a  certain  shape,  so  that  when  the  whole 
"  sandwich  "  is  compressed  under  the  blows  of  the 
hammer  and  the  soft  metal  is  pressed  into  the 
depressions  the  desired  shape  is  formed. 

Next  we  see  "  flanging  presses,"  in  which  thick 
steel  plates,  after  being  made  hot,  are  pressed  into 
curious  shapes  almost  as  easily  as  one  can  shape 
tinfoil  between  the  fingers. 

These  are  parts  for  the  boiler  shop,  into  which  we 
pass  next.  As  usual  with  boiler  shops,  the  chief 
feature  which  strikes  the  visitor  is  the  noise.  The 
hammer  is  a  famous  tool  in  the  hands  of  a  boiler- 
maker.  It  may  be  that  he  is  flattening  a  plate,  or 
trimming  its  edge,  or  caulking  the  joints,  or  closing 
down  a  rivet,  or  putting  in  stays,  whatever  it  is  he 

52 


WHERE  THE  LOCOMOTIVES  ARE  MADE 

may  be  doing  it  is  almost  sure  to  be  a  hammer  that 
he  is  using. 

Then  the  hand  hammer  is  powerfully  reinforced 
by  the  pneumatic  "  pistol "  hammer,  so  called 
because  the  workman  holds  it  in  his  hand  like  a 
pistol.  Like  a  pistol,  too,  it  has  a  trigger,  upon 
pressing  which  a  little  steel  hammer-head  inside  the 
tool  strikes  rapidly  upon  the  chisel  or  riveting  tool 
or  whatever  it  may  be  that  is  placed  in  the  "  muzzle." 
The  result  is  a  fierce  growl,  more  menacing  than 
the  cry  of  the  noisiest  animal,  yet  it  is  simply  doing 
some  useful  and  beneficial  work. 

Look  at  that  man,  for  example.  He  is  putting  in 
some  rivets  to  fasten  together  two  steel  plates  which 
will  shortly  form  part  of  a  boiler.  There  are  holes 
along  the  edge  of  both  plates,  carefully  drilled  so 
that  they  will  coincide.  Into  these  holes  are  placed, 
one  at  a  time,  of  course,  hot  rivets.  The  man  with 
the  pistol  then  holds  its  muzzle  (or  rather  a  tool 
stuck  in  the  muzzle)  against  the  end  of  the  rivet, 
presses  the  trigger  and  amid  a  terrific  din  the  solid 
steel  just  flattens  down  into  a  pan-shaped  head. 

But  we  must  hurry  on,  simply  pausing  to  notice 
the  shearing  machine.  Here  a  pair  of  steel  jaws 
are  continually  opening  and  shutting.  A  man 
places  a  piece  of  steel  plate  three-quarters  of  an  inch 
thick  between  them,  and  in  less  time  than  it  takes 
me  to  write  this  the  plate  is  bitten  cleanly  in  two. 

The  iron  foundry  takes  our  attention  next.  It 
is  a  lofty  building  with  an  electric  crane  overhead, 
but  it  must  be  confessed  that  it  is  dirty.  It  is  "  clean  " 
dirt,  however,  for  it  is  due  to  the  dust  of  the  black 

53 


WHERE  THE  LOCOMOTIVES  ARE  MADE 

sand  of  which  the  floor  is  composed  and  of  which 
the  moulds  are  made,  and  that  is  kept  sweet  and 
healthy  by  frequent  contact  with  molten  iron. 

All  over  the  floor  are  men  or  little  groups  of  men 
making  the  moulds.  Let  us  watch  one.  He  is  only 
doing  a  simple  job,  but  it  will  serve  to  illustrate  all. 
He  is  making  some  brake  blocks  for  a  tender,  those 
things  which  press  against  the  wheels  when  it  is 
desired  to  check  the  speed. 

Lying  upon  the  floor  is  a  board  with  some  curiously 
shaped  projections  upon  it,  which  upon  closer 
examination  prove  to  be  each  one -half  of  a  brake 
block.  Those  projections  are  the  "  patterns  "  which 
in  this  case  are  for  convenience  mounted  upon  a 
board. 

Then  he  takes  an  iron  box  which  he  carefully 
lays  down  upon  the  board,  with  its  open  end  down- 
wards. The  other  end  of  the  box,  the  bottom  we 
might  call  it,  now  lies  upwards,  and  we  notice  that 
it  has  no  bottom  in  the  usual  sense,  but  instead  a 
number  of  crossbars  with  spaces  in  between.  He  is 
now  filling  the  box  with  sand,  passing  it  in  between 
the  crossbars,  spreading  it  so  that  it  covers  the 
patterns  entirely.  Now  he  takes  up  a  rammer  and 
with  it  beats  the  sand  as  hard  as  he  can,  adding  more 
and  more  sand  until  the  box  is  quite  full  of  sand 
now  as  firm,  almost,  as  a  brick. 

Next  he  carefully  lifts  the  box  off  the  patterns 
and  turns  it  over,  revealing  a  surface  of  sand  with 
depressions  in  it,  each  of  them  being  a  negative,  so 
to  speak,  of  half  a  brake  block.  This  is  the  bottom 
part  of  a  mould. 

54 


WHERE  THE  LOCOMOTIVES  ARE  MADE 

In  a  similar  manner  he  makes  a  top  part,  which 
when  put  together  with  the  bottom  one  will  form  a 
complete  mould.  Suitable  locating  pegs  and  holes 
ensure  that  the  depressions  in  the  bottom  part  shall 
eventually  correspond  exactly  with  the  depressions 
in  the  top  part,  so  that  when  the  cavities  so  formed 
are  filled  with  metal  the  result  will  be  a  complete 
brake  block. 

In  the  course  of  this  operation  he  cuts  holes  and 
channels  in  the  sand  with  a  trowel,  through  which  to 
pour  the  iron,  and  finally  he  clamps  the  boxes  together 
in  order  to  prevent  the  possibility  of  the  top  one 
floating  when  the  metal  is  poured  in. 

In  other  parts  of  the  foundry  we  see  other  moulds 
being  made,  some  very  much  larger  and  more  com- 
plicated, but  they  are  all  done  on  the  same  principle. 

Suddenly  a  warning  shout  makes  us  turn  our  heads 
to  find  the  travelling  crane  hurrying  along  the  shop 
carrying  a  large  ladle,  like  a  gigantic  bucket.  As  it 
approaches  us  we  feel  that  it  is  intensely  hot,  and  a 
nearer  view  reveals  that  the  inside  is  bright  red  with 
heat.  It  has  just  poured  its  recent  load  of  molten 
iron  into  a  mould  and  is  returning  to  the  furnace  for 
more.  Suppose  we  follow  it. 

The  furnace  is  outside  the  building,  but  a  spout 
projects  through  the  wall,  and  just  as  we  arrive  we 
see  a  man  chip  out  a  little  plug  of  clay  which  till 
then  had  sealed  a  small  hole  at  the  far  end  of  the 
spout.  Instantly  a  stream  of  white-hot  liquid  com- 
mences to  trickle  down  the  spout  and  pour  into  the 
ladle  waiting  to  receive  it. 

While  waiting  for  it  to  be  filled  we  can  notice  this 

55 


WHERE  THE  LOCOMOTIVES  ARE  MADE 

ladle.  It  is  made  of  steel  plates  riveted  together 
like  a  boiler,  but,  inside  it,  is  a  thick  lining  which 
our  guide  tells  us  is  made  of  sand.  The  sand  is 
made  into  a  sort  of  mortar  and  spread  on,  then  a 
fire  is  made  inside  to  dry  it  and  bake  it  hard,  after 
which  it  is  ready  for  use.  The  lining  has  to  be 
renewed  daily. 

The  ladle  is  now  full  and  the  furnace  man  seals 
the  "  tapping  hole  "  once  more,  the  crane  hurries 
off  with  the  full  ladle,  and  if  we  wish  to  see  the 
moulds  filled  we,  too,  must  hurry.  On  reaching  where 
the  mould  lies  we  see  the  ladle  being  tipped  by  one 
man,  while  another  with  a  long  rod  clears  the  dross 
from  off  the  top  of  the  metal ;  a  third  meanwhile 
stirs  the  metal  and  others  stand  around  in  case  of 
need.  Altogether,  the  pouring  of  a  big  casting  is 
an  exciting  as  well  as  a  picturesque  and,  it  may  be 
added,  a  warm  undertaking. 

Leaving  the  foundry,  since  time  is  getting  on,  we 
just  glance  at  the  tall,  steel  tube  standing  vertically 
outside  the  foundry  which  constitutes  the  furnace 
or  "  cupola,"  to  give  it  its  professional  name.  It  is 
about  5  ft.  in  diameter  and  as  high  as  a  two  story 
house.  Composed  of  steel  plates  riveted  together, 
it  has  a  lining  of  fire-brick,  while  near  the  bottom  it 
is  encircled  by  a  hollow  belt  through  which  air  is 
blown  into  the  fire,  the  compressed  air  being  derived 
from  a  fan  or  blower  in  a  smaller  house  near  by. 

Coke  and  pig  iron  are  fed  in  through  a  hole  near 
the  top,  the  men  working  upon  a  stage  placed  high 
up  for  the  purpose. 

In  the  brass  foundry,  which  we  visit  next,  the 

56 


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WHERE  THE  LOCOMOTIVES  ARE  MADE 

metal  is  melted  in  crucibles  in  furnaces  beneath  the 
floor.  The  moulds  are  made  in  a  similar  way  and 
are  filled  from  the  crucibles,  which  are  lifted  out 
bodily  and  carried  in  a  kind  of  cradle  by  two  men. 

When  the  castings  have  cooled,  the  moulds  are 
broken  and  the  rough  castings  are  pulled  out.  In 
the  case  of  iron  they  are  dressed  with  wire  brushes 
to  get  the  sand  off,  and  little  excrescences  are  cut 
off  with  a  hammer  and  chisel,  a  process  called 
"fettling."  The  "runners,"  too,  the  metal  which 
remained  in  the  channels  formed  to  pour  the  iron 
through,  are  cut  off  usually  with  a  chisel. 

Brass  castings,  being  of  a  softer  nature,  are  some- 
times treated  differently.  Here,  as  we  pass  on  our 
tour,  we  see  a  sand-blast  chamber,  a  cabin  built  of 
steel  plates  with  a  little  window  through  which  we 
can  look.  There  we  see  a  man  in  a  dress  something 
like  that  of  a  diver,  holding  in  his  hand  a  tool  like 
a  pistol  at  the  end  of  a  pipe.  He  points  the  "  pistol  " 
at  a  rough  brass  casting  and  lo  !  it  becomes  almost 
instantly  clean  over  a  considerable  patch  opposite 
the  muzzle.  As  he  moves  the  tool  about  the  clean 
patch  spreads  until  the  thing  is  soon  clean  all 
over. 

Having  finished,  he  lays  down  his  "  weapon," 
takes  off  his  helmet  and  opens  the  door  of  his  prison. 
Looking  through  the  door  we  can  now  see  more  of 
the  apparatus. 

He  wears  a  helmet  to  keep  the  dust  from  his 
lungs.  The  pistol  is  supplied  with  compressed  air 
from  a  machine  just  outside  the  cabin,  and  the 
jet  of  compressed  air  carries  with  it  innumerable 

57 


WHERE  THE  LOCOMOTIVES  ARE  MADE 

little  pellets  of  iron,  called  "  chilled  iron  shot."  It 
is  this  jet  of  air,  reinforced  by  the  shot,  which  so 
quickly  cleans  the  castings.  The  shot,  having  done 
its  work,  falls  on  the  floor,  drops  through  the  tiny 
perforations  with  which  the  floor  is  pierced  and  is 
sucked  away  to  be  used  over  again. 

Close  by  another  strange  machine  demands  our 
attention.  Before  it  there  stands  a  man  with  a 
brass  casting  in  his  hand  just  as  it  came  out  of  the 
sand,  with  the  "  runner  "  adhering  to  it.  He  inserts 
this  between  two  teeth  with  which  the  machine  is 
armed,  presses  a  pedal  and  in  a  second  the  teeth 
come  together  and  bite  off  the  runner  just  as  a  boy 
bites  a  piece  of  cake. 

Lastly  we  reach  the  crowning  experience  of  all, 
the  shop  where  the  engines  are  erected,  where  the 
parts  from  all  the  other  shops  come  together  and  are 
combined  into  the  wonderful  machines  which  draw 
the  trains  along. 

It  is  a  large  and  lofty  shop  with  the  inevitable 
electric  crane  overhead.  Running  lengthwise  of  the 
shop  are  many  pairs  of  rails,  all  of  which  merge 
together  into  one  at  one  end.  Between  the  rails 
are  the  "  pits "  over  which  the  engines  are  put 
together,  and  in  which  the  men  can  stand  when  they 
need  to  work  at  the  underneath  side  of  the  engines. 

First  the  framework  is  built  up,  being  supported 
upon  screw  jacks.  Then  the  cylinders  are  put  in 
place  and  many  other  less  important  parts,  then  the 
frame  is  lifted  by  the  crane,  the  jacks  taken  away 
and  the  wheels  run  underneath.  Then  the  boiler 
is  lifted  on  to  the  frame  and  properly  fitted  to  it, 

58 


WHERE  THE  LOCOMOTIVES  ARE  MADE 

and  thus  the  engine  grows  bit  by  bit  until  it  is  ready 
to  go  forth  for  its  trials. 

There  is  little  machinery  in  this  shop.  The  final 
assembling  together  has  to  be  done  very  largely  by 
human  agency,  for  after  all  the  human  frame  is  the 
most  adaptable  machine  in  existence.  For  varied 
and  delicate  work  the  human  fingers  and  hands  are 
supreme. 

So  there  we  have  an  impression,  necessarily  a  very 
superficial  one,  of  a  stroll  through  a  locomotive 
works.  A  whole  book  could  be  devoted  to  it,  for 
there  are  many  things  not  even  mentioned  in  this 
description,  but  a  general  idea  is  always  of  value, 
since  it  can  be  added  to  and  the  spaces  filled  in  as 
we  add  to  our  store  of  knowledge. 


59 


CHAPTER  IV 
HOW  A  LOCOMOTIVE  WORKS 

THERE  is  no  doubt  that  the  most  fascinating 
feature  of  the  railway  is  the  steam  loco- 
motive. There  is  something  almost  human 
about  it.  Few  sights  are  more  impressive  than  the 
slow,  dignified  entry  of  a  big  engine,  with  a  heavy 
train  behind  it,  as  it  draws  up  in  a  terminus  after  a 
long  run.  One  almost  feels  a  desire  to  pat  it  on  the 
back  as  one  would  do  to  a  friend  who  had  accom- 
plished an  athletic  feat  with  credit  to  himself  and 
his  associates. 

Now  how  does  this  wonderful  machine  work  ? 
To  the  casual  observer  it  looks  very  mysterious 
and  difficult  to  understand,  but  if  we  take  it  a 
part  at  a  time  we  shall  find  that  it  is  really  very 
simple. 

Let  us  start  with  the  boiler.  When  we  look  upon 
what  we  deem  to  be  the  boiler  of  a  locomotive  we 
are,  in  fact,  merely  looking  at  the  covering  which 
is  put  around  the  real  boiler  for  the  purpose  in- 
cidentally of  making  it  look  nice,  but  chiefly  to  keep 
the  heat  in.  The  boiler  itself  is  really  a  rather  ugly 
structure  of  steel  plates  with  unsightly  seams  and 
studded  with  rivet-heads.  Around  that  is  placed  a 
layer  of  non-conducting  composition,  then  a  layer 

Q 


HOW  A  LOCOMOTIVE  WORKS 

of  wood  laths  and  finally  a  coat  of  smooth  sheet 
iron,  which  last  is  made  beautiful  by  skilful 
painting. 

The  boiler  itself  is  cylindrical,  but  it  is  supported 
at  each  end  in  a  kind  of  box,  the  front  one  being  the 
smoke-box  and  the  hind  one  the  fire-box. 

The  ends  of  the  boiler  are  closed  by  steel  plates 
perforated  by  a  number  of  holes  into  which  tubes 


FIRE 
BOX  v 

FIRE  BARS 

FORMING 

HEARTH 


0> 


END  OF 
STEAM  PIPE 

Boiler  Proper 


END  OF  BLAST 
PIPE 


SMOKE  BOX 


TUBES  THROUGH  WHICH  PASS  HOT 
CASES  FROM    FfRE 


Fig.  1. 

This  diagram  is  intended  to  give  a  general  idea  of  the  internal 
construction  of  the  boiler  of  a  locomotive  * 

are  fitted,  each  tube  running  straight  through  from 
fire-box  to  smoke-box. 

The  flames  and  hot  gases  from  the  fire  in  the  fire- 
box thus  pass  through  the  tubes  into  the  smoke-box, 
and  in  doing  so  heat  the  water  which  surrounds  the 
tubes.  The  purpose  of  this  form  of  construction 
is  to  obtain  as  large  an  area  as  possible  through 

*  Wherever  the  word  "diagram"  is  used  in  connection  with  an 
illustration,  it  should  be  clearly  understood  that  the  drawing  is 
not  an  exact  representation  of  the  object. 

It  is  probably  not  to  scale  and  certain  details  may  be  left  out 
and  others  modified.  This  is  done  in  order  that  the  general  principle 
of  the  thing  may  stand  out  clearly. 


61 


HOW  A  LOCOMOTIVE  WORKS 

which  heat  can  pass  from  the  hot  gases  into  the 
water.  In  stationary  boilers  this  result  is  attained 
in  a  different  way,  but  this  is  the  best  way  to  do  it 
in  the  limited  space  available  on  a  locomotive. 

It  may  be  mentioned  in  passing  that  there  are  a 
lot  of  things  which  the  locomotive  engineer  would 
like  to  do  differently,  but  he  is  prevented  by  the 
limitations  of  size. 

The  fire-box  is  itself  made  double,  like  one  box 
inside  another,  so  that  the  inner  box  which  contains 
the  fire  is  practically  surrounded  by  water  which  is 
in  free  communication  with  the  water  in  the  boiler 
proper.  This,  again,  is  to  obtain  greater  heating 
surface. 

There  is  a  furnace  inside  this  inner  shell  of  the 
fire-box  with  a  floor  of  fire-bars,  upon  which  rests 
the  fire  from  which  the  whole  energy  of  the  engine 
comes. 

The  boiler  of  a  locomotive  is  really  too  small  for 
its  work.  It  would  be  better  if  there  were  more 
space  in  it  for  the  storage  of  steam.  In  other  words, 
it  works  more  nearly  full  of  water  than  is  desirable, 
and  one  of  the  results  of  this  is  that  steam  taken 
from  the  upper  part  of  it  is  "  wet,"  which  means  that 
it  contains  a  lot  of  tiny  globules  of  water  and  is  not 
pure  steam.  These  globules  tend  to  fill  the  cylinder 
with  water  and  prevent  it  working  properly,  a  fact 
which  gives  rise  to  the  use  of  a  steam  dome,  that 
familiar  feature  on  the  back,  so  to  speak,  of  most 
locomotives. 

The  dome  is  a  kind  of  excrescence  growing  out  of 
the  boiler,  and  the  pipe  through  which  the  steam  is 

62 


HOW  A  LOCOMOTIVE  WORKS 

drawn  out  has  its  open  end  right  up  inside  this,  as 
high  above  the  surface  of  the  water  as  possible.  The 
higher  a  point  is  above  the  water  the  less  water 
particles  are  there,  and  consequently  this  pipe 
obtains  the  steam  in  the  dryest  possible  condition. 

Entering  the  open  end  of  the  eduction  or  "  leading 
out  "  pipe,  the  steam  flows  down  and  then  along, 
by  the  most  convenient  route,  to  the  cylinders, 
passing  on  its  way  the  regulator  valve  by  which  the 
whole  wrork  of  the  engine  is  controlled.  This  valve 
is  so  placed  that  a  rod  can  conveniently  pass  to  the 
cab  where  the  driver  is,  and  upon  the  end  of  this 
rod  is  the  familiar  handle  or  "  regulator  "  by  means 
of  which  the  driver  can  start,  stop  and  regulate  the 
speed. 

In  the  cab  there  are  a  number  of  other  devices 
besides  the  regulator,  the  most  important  of  which 
are  the  pressure  gauge  and  the  gauge  glass. 

The  pressure  gauge  is  in  appearance  like  a  clock 
with  one  hand.  The  figures  round  the  dial  represent 
"  pounds  per  square  inch,"  and  thus  the  position  of 
the  hand  tells  the  driver  at  any  moment  what  is  the 
pressure  of  the  steam  in  his  boiler.  It  is  able  to  tell 
him  this  because  it  is  connected  by  means  of  a  tube 
to  the  interior  of  the  boiler  itself.  It  is  itself  of  a 
wonderfully  simple  construction,  there  being  little 
inside  the  case  except  a  bent  tube  sealed  at  one  end, 
but  in  communication  with  the  boiler  at  the  other. 
Fluid  pressure  inside  a  bent  tube  tends  to  straighten 
it,  and  so  as  the  pressure  rises  the  bent  tube  more 
and  more  straightens  itself,  which  movement  is  made 
to  turn  the  hand. 

63 


HOW  A  LOCOMOTIVE  WORKS 

If  you  notice  carefully  you  will  see  that  this  gauge 
generally  surmounts  another  bent  tube,  this  one 
being  on  the  outside.  The  purpose  of  this  is  to  protect 


STEAM  ENTERS 


Fig.  2.— How  THE  STEAM  REACHES  THE  CYLINDER, 

With  the  slide  valve  in  the  position  shown,  the  staam  finds 
the  right-hand  port  open,  and  passing  through  it  enters  the 
right-hand  end  of  the  cylinder  and  pushes  the  piston  towards 
the  left. 

Meanwhile,  the  steam  left  in  after  the  previous  stroke  is 
pushed  out  through  the  left-hand  port  and  led  to  the  centre 
port,  through  which  it  escapes  to  the  chimney. 

As  the  piston  is  moved  by  the  steam  it  in  turn  moves  the 
slide  valve  until  it  reaches  the  position  shown  dotted.  The 
whole  operation  is  then  reversed  and  the  piston  is  pushed  back. 

All  parts  are  here  shown  as  if  cut  in  half,  and  the  rod  that 
moves  the  valve  is  left  out  altogether. 

the  gauge  from  the  effects  of  the  varying  temperature 
of  the  steam  ;  the  water  which  quickly  collects  in 
the  curl  of  this  tube  maintains  a  fairly  even  tem- 
perature, so  that  it  shields  the  gauge  from  these 

64 


HOW  A  LOCOMOTIVE  WORKS 

variations,  yet  it  transmits  the  changes  in  pressure 
very  readily. 

The  gauge  glass  is  a  vertical  tube  of  glass  carried 
in  brass  fittings  which  are  in  communication  with 
the  interior  of  the  boiler,  so  that  as  the  level  of  the 
water  rises  and  falls  in  the  boiler  it  does  the  same  in 
the  tube,  and  by  looking  at  the  tube  the  driver  can 
see  at  any  moment  what  is  the  level  of  the  water 
inside. 

Let  us  now  turn  our  attention  to  the  "  smoke-box  " 
at  the  other  end.  The  hot  gases  from  the  fire,  and 
the  smoke  when  there  is  any,  come  through  the 
tubes  into  the  smoke-box  and  then  find  their  way  up 
the  chimney,  which  is  really  a  continuation  upwards 
of  the  smoke-box  itself. 

In  addition  to  this  there  is  a  pipe  with  an  open 
end  standing  up  vertically  precisely  under  the 
chimney.  This  is  the  "  blast-pipe,"  and  is  one  of 
the  most  important  features  of  the  engine.  It  was 
the  invention  of  the  "  blast -pipe "  by  George 
Stephenson  which  more  than  anything  else  made  the 
locomotive  a  success. 

Through  this  pipe  comes  the  "  exhaust  steam  " 
from  the  cylinders.  If  the  locomotive  were  a  per- 
fectly efficient  engine  this  steam  would  have  little 
or  no  force  in  it,  but,  in  fact,  it  shoots  up  from  the 
"  blast-pipe  "  with  a  very  considerable  force,  and 
in  so  doing  creates  a  strong  draught  up  the  chimney. 
This  sucks  the  gases  through  the  tubes  and  so  draws 
air  into  the  furnace,  causing  the  fire  to  burn  strongly 
and  enabling  steam  to  be  kept  up.  In  the  early 
engines  it  was  found  almost  impossible  to  maintain 
E  65 


HOW  A  LOCOMOTIVE  WORKS 

the  supply  of  steam  from  a  boiler  really  too  small 
for  its  work,  but  the  happy  idea  of  blowing  the  exhaust 
steam  up  the  chimney  in  this  way  solved  the  diffi- 
culty completely. 

The  blast  is,  of  course,  only  at  work  when  the 
engine  is  running,  so  it  is  reinforced  by  a  smaller 
pipe  of  a  similar  kind,  called  the  "  blower,"  by  which, 
when  the  engine  is  at  rest,  the  driver  can  direct  a 
jet  of  steam  straight  from  the  boiler  up  the  chimney 
to  do  the  work  of  the  blast.  The  steam  jet  is  con- 
trolled by  a  handle  in  the  cab. 

So  much  for  the  boiler  ;  let  us  now  turn  our  atten- 
tion to  the  "  engine  "  proper. 

The  most  important  part  is,  of  course,  the  cylinder, 
a  box  made  of  cast  iron,  the  inside  truly  cylindrical 
and  smooth,  in  which  there  slides  to  and  fro  a  second 
cylindrical  object  called  the  "  piston."  The  steam 
enters  first  at  one  end  and  then  at  the  other,  thereby 
pushing  the  piston  from  end  to  end,  first  one  way 
and  then  the  other.  A  rod,  called  the  "  piston-rod," 
communicates  this  motion  through  one  of  the 
"  covers  "  of  the  cylinder  to  the  crank. 

That  brings  us  to  the  most  important  part  of  all, 
the  valve  which  automatically  distributes  the  steam 
to  the  two  ends  alternately  and  at  the  same  time 
liberates  the  old  steam  which  has  done  its  work. 
It  is  called  a  "  slide  valve  "  because  its  mode  of  work 
is  to  slide  backwards  and  forwards  upon  a  smooth 
surface. 

This  surface,  which  is  termed  the  "  valve  face," 
is  formed  on  one  side  of  the  cylinder  casting.  A  box- 
like  part  is  inverted  over  the  valve  face  so  that  the 

66 


HOW  A  LOCOMOTIVE  WORKS 

face  forms,  as  it  were,  the  floor  of  a  rectangular 
chamber,  called  the  "  steam  chest."  The  steam 
enters  the  "  steam  chest  "  through  an  orifice  made 
for  the  purpose  and  thence  passes  to  the  "  ports," 
passages  formed  in  the  walls  of  the  cylinder  which 
terminate  in  holes  in  the  steam  chest. 

There  is  one  hole  from  which  a  port  leads  to  one 
end  of  the  cylinder  and  another  hole  whence  a  port 
leads  to  the  other  end.  In  between  these  is  a  third 
hole  which  is  really  the  entrance  to  the  "  exhaust 
port,"  a  passage  leading  out  of  the  cylinder  altogether. 

Were  there  nothing  more  than  this,  then,  steam 
entering  the  steam  chest  would  pass,  some  to  one 
end  of  the  cylinder,  some  to  the  other,  while  some 
would  escape  altogether. 

The  valve,  however,  changes  all  this.  It  is  like  a 
lidless  box  placed  open  end  downwards  upon  the 
valve  face.  Assuming  it  to  be  at  one  end  steam 
entering  the  steam  chest  finds  two  of  the  holes 
covered,  so  that  it  can  only  pass  to  one  end  of  the 
cylinder.  It,  therefore,  will  push  the  piston  to  the 
other  end.  Suppose  now  that  the  slide  valve  be 
also  pushed  to  the  other  end.  The  port  throngh 
which  the  steam  has  just  gone  in  will  be  closed  aud 
the  other  one  uncovered.  Steam  will  now  enter  at 
the  opposite  end  and  the  piston  will  be  pushed  back 
again. 

But  what  will  happen  to  the  first  lot  of  steam  that 
went  in  ?  It  will  come  out  through  the  same  port 
by  which  it  entered,  but  this  time  it  will  go  into  the 
inside  of  the  slide  valve.  Now  the  slide  valve  is  so 
arranged  that  the  centre  port,  that  which  leads  to 

67 


HOW  A  LOCOMOTIVE  WORKS 

the  open  air,  is  always  open  to  the  inside  of  the  valve. 
Consequently,  as  the  old  steam  comes  out  from  the 
port  into  the  inside  of  the  valve,  it  finds  a  ready 
means  of  escape  through  the  "  exhaust  port." 

To  put  it  another  way,  the  action  of  the  slide 
valve  is  to  uncover  one  steam  port  and  to  connect 
the  other  one  to  the  exhaust  port,  and  this  it  does 
at  the  two  ends  alternately.  If  this  description  is 
not  clear  a  glance  at  the  diagram  on  page  64  will 
be  of  material  assistance.  It  is  worth  a  little  trouble 
to  get  a  thorough  understanding  of  this,  the  most 
essential  part  of  every  steam  engine. 

In  some  of  the  most  modern  engines  the  simple 
slide  valve  gives  place  to  a  "  piston  valve,"  the  form 
of  which  is  slightly  different,  although  the  principle 
is  the  same.  The  piston  valve  consists  of  two  pistons 
connected  by  a  rod  working  in  a  small  cylinder 
alongside  the  main  cylinder. 

In  all  these  parts  "  steam-tightness  "  is  the  great 
thing  to  be  sought  after.  The  piston  needs  to  slide 
freely  in  the  cylinder,  but  it  must  not  allow  any 
steam  to  slip  past,  and  it  seems  at  first  sight  that  if 
the  piston  be  loose  enough  to  move  freely  steam  will 
inevitably  get  past  it.  Or  to  put  it  the  other  way, 
if  it  be  tight  enough  to  prevent  the  passage  of  steam 
(for  we  know  what  a  slight  crack  steam  can  get 
through)  it  must  be  too  tight  to  move  freely. 

This  apparent  dilemma  is  avoided  in  this  simple 
way.  The  piston  is  made  quite  a  loose  fit  in  the 
cylinder,  but  around  its  edge  is  turned  a  groove,  and 
in  this  groove  there  fit  a  number  of  spring  rings. 
These  rings  spring  outwards,  so  that  they  keep  up  a 

68 


HOWjV  LOCOMOTIVE  WORKS 

gentle  pressure  upon  the  cylinder  walls,  making  a 
perfect  joint  against  them,  past  which  no  steam  can 
escape,  yet  their  pressure  is  so  slight  that  they  do 
not  interfere  in  any  way  with  the  free  movement  of 
the  piston. 

The  slide  valve  is  made  steam-tight  in  an  even  more 
simple  manner.  The  valve  face  is  planed  flat  and 
smooth,  and  so  is  the  face  of  the  valve  which  comes 
into  contact  with  it.  Then  each  one  is  rubbed  with 
a  flat  piece  of  steel  on  which  has  been  smeared  some 
red  paint.  This  at  once  reveals  any  slight  irregu- 
larities, which  are  forthwith  removed  by  scraping 
by  hand.  A  careful  workman  can  soon  make  the 
two  surfaces  so  flat  that  no  steam  can  pass  between. 

The  outer  end  of  the  piston  rod  terminates  in  the 
"  cross-head,"  a  block  of  steel  which  slides  to  and 
fro  between  a  pair  of  guides.  To  this  is  pivoted  one 
end  of  the  "  connecting  rod,"  the  other  end  of  which 
grasps  the  "  crank  "  which  is  formed  upon  the  axle 
of  the  driving  wheels,  or  in  some  cases  upon  the  driving 
wheel  itself. 

Thus,  as  the  piston  moves  to  and  fro,  its  motion 
is  communicated  to  the  cross-head,  and  that  again 
is  changed  by  the  connecting  rod  and  crank  into 
the  round  and  round  motion  of  the  wheels. 

The  next  question  that  presents  itself  is,  how  is 
an  engine  reversed  ? 

To  answer  that  we  must  first  see  how  the  valve  is 
moved.  It  is  clear  that  the  working  of  the  valve 
must  be  automatic,  and  the  simplest  thing  would 
seem  to  be  to  connect  it  with  the  piston  rod.  The 
difficulty  arises  there,  however,  that  the  valve  needs 

69 


HOW  A  LOCOMOTIVE  WORKS 

to  be  in  the  middle  of  its  stroke  just  when  the  piston 
is  at  one  end.  A  study  of  the  diagram  on  page  64 
will  show  why  this  is  so. 

A  simple  way  to  do  it  would  be  to  put  an  extra 
crank  upon  the  main  axle  at  right  angles  to  the  main 
crank,  and  to  connect  that  crank  by  means  of  two 
rods,  similar  to  the  connecting  rod  and  the  piston 
rod,  to  the  valve.  That  is,  in  effect,  what  is  done, 
but  instead  of  a  second  crank  an  eccentric  is  generally 
employed.  This  is  a  round  disc  mounted  upon  the 
shaft  by  means  of  a  hole  out  of  its  centre.  A  strap, 
called  the  eccentric  strap,  encircles  this,  and  this 
strap  is  connected  by  the  "  eccentric  rod  "  to  the 
valve  rod.  Thus  as  the  eccentric  "  wobbles  "  round 
inside  the  strap  it  gives  a  to-and-fro  motion  to  the 
valve  just  as  a  crank  would  do.  An  eccentric  rod  is 
for  practical  reasons  preferred  to  a  crank  ;  it  takes 
up  less  room  on  the  axle  and  does  not  weaken  it  at 
all  as  a  crank  does. 

In  some  engines,  particularly  where  the  cylinders 
are  on  the  outside  of  the  frame,  this  arrangement  is 
for  practical  reasons  impossible,  and  in  such  cases 
an  ingenious  series  of  levers  is  made  to  produce  the 
same  result. 

And  now  we  can  see  how  to  reverse  the  engine. 
As  we  have  seen  from  the  diagram  on  page  64, 
let  us  imagine  the  slide  valve  in  the  middle  position. 
If  the  valve  then  moves  to  the  right  the  piston  will 
follow  it  in  the  same  direction.  If  it  moves  to  the 
left  the  piston  will  also  move  to  the  left.  Thus  to 
reverse  the  direction  of  the  engine  all  we  need  to  do 
is  to  reverse  the  action  of  the  slide  valve. 

70 


HOW  A  LOCOMOTIVE  WORKS 


Imagine,  therefore,  two  eccentrics  set  upon  the 
axle  side  by  side,  but  with  their  big  sides  opposite 
to  each  other.  There  will  be  two  straps  and  two 
eccentric  rods,  and  as  the  axle  turns  one  rod  will 
always  be  pulling  as  the  other  is  pushing.  Now  let 
these  two  rods  terminate  in  a  "  link  "  something 


REVERSING 
ROD 


C  CENTRIC 


THIS  WORKS 

UP    AND 
DOWN  IN  LINK 


Fig.  3.  —  How  AN  ENGINE  is  REVERSED. 

(Suppose  that  the  two  axles  are  so  connected  that  they 
turn  as  one.) 

The  two  eccentrics  cause  the  link  to  rock  like  a  see  -saw.  Aa 
shown  above,  therefore,  the  valve  will  not  be  worked  at  all, 
because  its  rod  is  connected  to  the  centre  of  the  link. 

If  the  reversing  rod  be  pulled,  the  link  will  move  upwards 
and  the  valve  will  come  under  the  control  of  the  lower  eccen- 
tric. Likewise,  if  lowered,  the  upper  eccentric  will  take  control. 
Since  the  eccentrics  are  set  opposite  each  other,  the  action  of 
the  valve  is  thus  reversed. 

N.B.  —  In  practice  the  two  eccentrics  are  set  side  by  side 
upon  the  same  axle. 

like  an  elongated  chain-link,  only  made  smooth  and 
nicely  finished.  One  rod  is  attached  to  each  end  of 
the  link,  and  the  result  is  that  the  motion  of  the 
link  is  like  that  of  a  see-saw,  the  two  ends  always 
moving  in  opposite  directions.  The  valve  rod  is 
furnished  with  a  pin  which  fits  into  the  slot  in  the 
link,  and  there  are  a  series  of  rods  and  levers  by 


HOW  A  LOCOMOTIVE  WORKS 

which  the  link  can  be  raised  and  lowered  so  that 
either  eccentric  can,  at  will,  be  made  to  work  the 
valve.  When  the  link  is  up  one  eccentric  will  work 
it ;  when  it  is  down  the  other. 

Assuming,  then,  for  the  sake  of  simplicity,  that  the 
engine  has  stopped  with  the  piston  in  the  middle  of 
the  cylinder.  Which  way  the  engine  will  start  will 
depend  entirely  upon  which  eccentric  is  put  in 
control  of  the  valve. 

The  engine  need  not,  in  fact,  be  in  that  precise 
position,  for  sliding  the  link  up  or  down  will  at  any 
time  cause  the  action  to  be  reversed. 

This  is  the  "  link-motion  "  reversing  gear,  invented 
by  George  Stephenson  and  scarcely  altered  since 
his  time.  The  link,  of  course,  is  moved  up  or  down 
by  the  action  of  the  lever  or  screw  in  the  cab,  and  so 
the  driver  can  control  the  direction  of  movement 
of  his  engine. 

Every  locomotive  has  at  least  two  cylinders, 
and  each  of  them  works  on  to  a  separate  crank. 
The  two  cranks,  moreover,  are  set  at  right  angles. 
The  reason  of  this  is  that  a  single  cylinder  can  best 
exert  its  power  when  the  crank  is  in  one  position, 
namely,  at  right  angles  to  the  direction  of  the  piston 
rod  or  thereabouts.  As  it  gets  more  and  more  in 
line  with  the  piston  rod  it  loses  leverage,  and  there 
is  one  position  of  the  crank  where  the  piston  has  no 
turning  power  at  all.  If  the  cranks  were  set  opposite 
to  each  other  this  position  of  powerlessness  would 
occur  at  the  same  moment  for  both  of  them,  but 
when  at  right  angles  one  is  at  its  best  just  when  the 
other  is  at  its  weakest,  so  that  the  combined  action 

72 


HOW  A  LOCOMOTIVE  WORKS 

of  the  two  is  uniform  and,  moreover,  the  engine  can 
start  equally  well  from  all  positions. 

A  few  engines  have  three  cylinders  and  some  have 
four.  In  some  cases,  even  of  four-cylinder  engines, 
the  steam  goes  direct  from  the  boiler  to  all  of  them, 
but  in  others,  called  "  compound "  engines,  the 
steam  after  leaving  the  first  two  goes  either  to  one 
other,  very  large,  one,  or  else  to  two  others.  The 
advantage  of  this  it  would  be  well  to  explain,  but 
that  we  will  save  for  another  chapter. 

Engines  possess  three  types  of  wheels.  The  most 
important  are  the  driving  wheels,  which  are  actually 
turned  round  by  the  mechanism  and  which  by 
gripping  the  rails  propel  the  train  along.  These 
are  generally  near  the  centre  of  the  engine,  and  there 
are  frequently  others  before  and  behind,  wheels 
which  simply  help  to  carry  the  weight  and 
take  no  part  in  hauling  the  load.  These  are 
spoken  of  respectively  as  "  leading  "  and  "  trailing  " 
wheels. 

It  is  by  the  numbers  of  these  wheels  that  the  type 
of  engine  can  be  described.  It  seems  strange  to  sum 
up  the  characteristics  of  an  engine  by  means  of  one 
feature,  but  these  are  so  fundamental  that  you  need 
only  tell  an  experienced  man  the  number  of  wheels 
of  these  three  types  for  him  to  gather  a  very  good 
general  idea  of  any  particular  engine. 

Thus  if  we  call  an  engine  a  4-4-0  we  mean  that  it 
has  four  leading  wheels,  four  driving  wheels,  and 
no  trailing  wheels.  If  we  say  0-4-2  we  mean  that 
it  has  no  leading  wheels,  but  that  it  has  four 
driving  wheels  and  two  trailing  wheels. 

73 


HOW  A  LOCOMOTIVE  WORKS 

Generally  the  power  from  the  pistons  is  communi- 
cated directly  to  cranks  upon  the  axle  of  one 
pair  of  driving  wheels,  and  the  other  driving 
wheels  are  coupled  to  the  first  pair  by  the  "  side- 
rods  "  which  are  such  a  familiar  feature  of  loco- 
motives. 

There  are  cases,  however,  of  engines  with  more 
than  one  pair  of  cylinders,  where  one  pair  drive  one 
pair  of  driving  wheels  and  the  other  or  others  drive 
another  pair  of  wheels.  However  that  may  be, 
there  are  always  side-rods  to  ensure  that  all  driving 
wheels  shall  pull  together,  except  in  that  dying  class 
of  fast  passenger  engines  where  only  a  single  pair  of 
driving  wheels  exist. 

Another  question  which  the  enquiring  mind  may 
raise  is  how  is  the  boiler  supplied  with  water  ?  Is 
it  pumped  ? 

An  injector  is  used  for  this  purpose.  As  the  name 
implies  this  throws  the  water  in.  It  does  not  push 
it  in  like  a  pump  does,  but  actually  throws  it.  It 
is  one  of  the  strangest  of  appliances,  for  in  it  a  jet 
of  steam  forces  the  water  into  the  boiler  against  the 
same  pressure  of  steam  trying  to  drive  it  out.  In 
other  words,  two  equal  pressures  meet,  yet  in  spite 
of  their  equality  one  seems  to  overpower  the  other. 
Briefly  the  arrangement  is  this  :  a  jet  of  steam  issues 
from  a  nozzle  and  enters  a  funnel  which  is  placed 
exactly  opposite  to  it ;  around  the  nozzle  is  water 
which  the  jet  carries  forward  and  to  which  it  imparts 
such  a  high  velocity  that  it  is  thrown  into  the  boiler 
in  spite  of  the  pressure  in  the  boiler  which  tends  to 
keep  it  out.  The  action  of  this  is  very  simple,  and 

74 


HOW  A  LOCOMOTIVE  WORKS 

is  specially  suited  to  the  work  required  of  it  on  a 
locomotive. 

The  water  is  carried  in  a  tank  in  the  tender,  in 
the  case  of  those  engines  which  have  tenders,  or  in 
the  case  of  those  without,  in  a  tank  or  tanks  on  the 
engine  itself.  That  is  why  engines  without  tenders 
are  termed  "  tank  "  engines. 

Frequently  there  are  three  types  of  brake  in  use. 
The  engine  itself  has  a  steam  break  in  which  steam 
in  a  cylinder  moves  a  piston  to  which  is  connected 
the  brake  gear.  When  the  piston  moves  it  therefore 
presses  the  brake  blocks  against  the  wheels.  The 
tender  usually  has  a  hand  brake  which  is  applied 
by  the  fireman  turning  a  handle.  Finally,  the  engine 
carries  the  apparatus  for  working  the  "  continuous  " 
brake  on  all  the  vehicles  of  a  passenger  train. 

All  engines  are  thus  fitted,  even  those  intended  for 
goods  traffic,  since  even  they  may  at  times  be  called 
upon  to  work  passenger  trains.  In  many  cases,  too, 
they  are  fitted  for  both  kinds  of  continuous  brake, 
so  that  they  can  work  whichever  type  their  train 
may  happen  to  possess. 

In  conclusion,  just  one  word  about  the  way  in 
which  engines  are  adapted  for  the  various  kinds  of 
work. 

A  goods  engine  needs  to  be  able  to  pull  heavy 
loads  at  moderate  speeds.  Hence  it  has  plenty  of 
driving  wheels  coupled  together,  to  give  it  plenty 
of  tractive  power.  Six  driving  wheels  is  very  usual 
and  sometimes  eight.  The  driving  wheels  are,  how- 
ever, relatively  small,  since  the  smaller  they  are  the 
more  easy  is  it  for  the  mechanism  to  turn  them. 

75 


HOW  A  LOCOMOTIVE  WORKS 

Passenger  engines,  having  to  handle  lighter  loads 
at  higher  speeds,  usually  have  no  more  than  four 
wheels  coupled,  and  the  diameter  is  larger.  To  run 
at  a  high  speed  the  smaller  wheels  of  the  goods  type 
would  have  to  turn  too  fast  for  the  welfare  of  the 
mechanism,  hence  for  fast  traffic  larger  wheels  are 
preferred. 

Long  journeys  without  stops  call  for  tender  engines 
because  of  the  quantity  of  water  needed.  On  the 
contrary,  when  frequent  stops  do  not  matter  it  is 
an  easy  thing  to  pick  up  water  at  wayside  stations, 
so  that  for  stopping  trains  tank  engines  are  the 
rule. 

Likewise,  for  heavy  traffic  on  heavy  roads,  that  is 
to  say  hilly  roads,  the  engines  have  to  be,  generally 
speaking,  of  a  heavier  type  than  those  in  use  on 
level  roads  where  also  the  traffic  happens  to  be 
light. 

It  is  all  these  considerations  which  account  for 
the  various  kinds  of  engines  to  be  found  on  different 
lines.  Each  line  has  developed  the  types  calculated 
to  deal  with  the  traffic  most  effectively  under  the 
conditions  which  prevail  upon  that  line. 


CHAPTER  V 
COMPOUND  LOCOMOTIVES 

familiar  "  puffing "  of  the  locomotive  is 
a  sign  that  good,  useful  energy  is  going  to 
waste.  If  the  locomotive  were  more  perfect 
the  steam  would  escape  from  the  chimney  just  like 
that  from  a  lightly  boiling  kettle,  without  any  force 
at  all. 

As  we  have  seen  already,  a  part  of  this  energy  is 
made  to  do  the  useful  work  of  fanning  the  fire, 
thereby  making  it  burn  well,  and  so  remedying  one, 
at  least,  of  the  weaknesses  inherent  in  the  loco- 
motive. Still,  even  when  that  has  been  allowed  for 
a  great  deal  of  waste  takes  place. 

To  understand  this  we  need  to  realize  that  steam 
under  pressure  is  like  a  coiled-up  spring.  Just  coil 
up  a  stout  clock  spring,  by  way  of  illustration,  and 
tie  it  with  string.  As  it  lies  upon  a  table  it  looks 
quite  feeble  and  without  energy,  but  cut  the  string 
and  it  will  fly  out  with  force  enough  to  give  you 
a  nasty  blow  should  it  strike  you. 

Now  when  you  turn  on  the  steam  to  a  steam  engine 
it  finds  its  way,  as  already  described,  through  the 
various  pipes  into  the  steam  chest,  then  through 
one  of  the  ports  into  the  cylinder,  where  it  pushes 
the  piston  from  one  end  of  the  cylinder  to  the  other. 

77 


COMPOUND  LOCOMOTIVES 

The  pressure  of  steam  in  the  boiler  when  the  valve 
was  opened  was,  let  us  say  for  the  sake  of  example, 
150  Ibs.  per  square  inch.  When  we  let  some  out 
into  the  steam  pipes  and  cylinder  the  pressure  tends 
to  fall,  but  that  is  prevented  by  the  fact  that  more 
and  more  steam  is  being  continually  given  off  by 
the  water  in  the  boiler.  We  arrive  at  the  fact, 
therefore,  that  boiler,  pipes  and  cylinder  are  all  full 
of  steam  at  150  Ibs.  per  square  inch  pressure.  Let 
us  now  close  the  valve,  so  that  no  more  steam  can 
enter ;  we  then  have  a  cylinder  full  of  steam  at 
150  Ibs.,  and  it  is  like  the  coiled-up  spring,  because 
if  we  let  it  out  it  will  expand  to  about  ten  times  its 
present  volume.  Or,  to  put  it  another  way,  if  we 
could,  by  a  miracle,  elongate  the  cylinder  to  about 
ten  times  its  present  length,  the  steam  already  in, 
without  any  further  help  from  outside,  could  push 
the  piston  to  the  further  end.  In  other  words,  when 
we  fill  the  cylinder  with  steam  at  boiler  pressure  the 
steam  has  still  a  great  deal  of  force  left  in  it  after  it 
has  pushed  the  piston  the  length  of  the  cylinder. 
We  will  call  this  the  "  expansive  force  "  of  the  steam. 

And  now,  please,  carry  your  thoughts  back  to  the 
description  of  the  steam  locomotive  and  its  reversing 
gear.  You  will  remember  that  it  is  reversed  by  the 
use  of  two  eccentrics,  each  of  which  operates  one 
end  of  a  link ;  the  two  eccentrics  are  set  opposite, 
so  that  the  link  rocks  like  a  see-saw  and  by  moving 
the  link  up  or  down,  as  the  case  may  be,  either  end 
can  be  made  to  work  the  slide  valve. 

Thus  the  centre  of  the  link  does  not  move  at  all.  If, 
then,  we  raise  the  link  slowly,  as  the  engine  is  at 

78 


COMPOUND  LOCOMOTIVES 

work,  the  slide  valve  is  moved  less  and  less  until, 
when  the  link  is  in  mid-position,  it  is  not  worked  at 
all ;  then,  if  we  continue,  the  amount  of  movement 
increases  again  until  it  is  once  more  moving  to  its 
full  extent.  So,  by  raising  or  lowering  the  link  we 
can  vary  the  stroke  of  the  slide  valve. 

In  actual  practice  this  is  done  and  by  it  a  good 
deal  of  saving  is  effected.  The  reversing  lever  works, 
as  you  have  probably  noticed,  between  guides 
shaped  like  a  quadrant,  and  in  the  quadrant  are 
notches  into  which  a  catch  engages,  so  that  the 
driver  can  fix  it  in  any  one  of  a  number  of  positions. 
As  the  engine  is  running  the  driver  "  notches  it  up," 
as  he  expresses  it,  meaning  thereby  that  he  moves 
his  reversing  lever  more  and  more  towards  its  central 
position.  If  he  put  it  in  the  central  position  he  would, 
of  course,  stop  his  engine  altogether,  since  in  that 
position  the  slide  valve  remains  still,  so  what  is  the 
purpose  of  this  operation  ? 

We  have  seen  that  after  filling  the  cylinder  with 
steam  there  is  still  enough  force  left  in  the  steam  to 
propel  the  piston  about  ten  times  as  far.  Suppose, 
then,  that  we  only  put  into  the  cylinder  enough 
steam  to  half-fill  it ;  the  expansive  force  will  push 
the  piston  the  other  half.  We  shall  thereby  reduce 
our  steam  consumption  by  half,  but  the  power 
generated  by  the  engine,  while  less  than  if  we  had 
filled  the  cylinder,  will  be  reduced  by  much  less  than 
half,  so  that  on  balance  our  engine  becomes  more 
efficient.  To  carry  the  idea  further,  if  we  cut  off 
the  supply  of  steam  when  the  cylinder  is  only  a 
quarter  full  we  shall  get  three-fourths  of  the  stroke 

79 


COMPOUND  LOCOMOTIVES 

done  by  the  expansive  energy  of  the  steam,  and 
so  on. 

When  new  steam  is  entering  the  cylinder  it  pushes 
with  practically  the  full  boiler  pressure  all  the  time, 
but  when  the  steam  is  working  by  expansion  its 
pressure  falls  rapidly.  Consequently,  when  starting, 
or  when  struggling  against  a  very  heavy  load,  the 
steam  may  be  admitted  during  practically  the  whole 
stroke,  but  when  the  train  is  under  way  and  the 
full  tractive  power  of  the  engine  is  not  required,  the 
driver  saves  steam,  and  therefore  coal,  by  working 
as  much  as  he  possibly  can  on  the  expansion  of  the 
steam. 

There  is  a  limit,  however,  to  the  amount  of  ex- 
pansion which  can  be  used  in  a  single  cylinder.  As 
the  steam  expands  it  cools  rapidly  and  so  chills  the 
cylinder  at  that  end  where  the  next  lot  of  steam 
will  enter.  Thus  if  the  expansion  be  carried  too  far 
the  steam  which  enters  for  the  next  stroke  will  be 
partially  condensed  by  the  cool  walls  of  the  cylinder 
and  power  will  thereby  be  lost. 

This  is  partly  obviated  in  some  of  the  most  modern 
locomotives  by  "  super-heating "  the  steam.  It 
should  be  understood  that  it  takes  a  certain  tem- 
perature to  convert  water  into  steam  at  any  given 
pressure.  As  the  pressure  rises  the  temperature  of 
the  steam  rises  too,  so  that  for  every  pressure  there 
is  a  corresponding  temperature.  We  might  call 
this  the  "  natural  "  temperature  corresponding  to 
the  pressure.  But  we  can  take  a  quantity  of  steam 
at  its  "  natural  "  temperature  and  heat  it  further. 
We  can,  in  fact,  heat  steam  just  as  we  can  heat  air 

80 


COMPOUND  LOCOMOTIVES 

or  any  other  vapour.  This  added  heat,  over  and 
above  the  "  natural  "  temperature,  we  call  "  super- 
heat." Its  chief  value  in  the  working  of  steam 
engines  is  that  steam  when  super-heated  has  a 
surplus  of  heat  which  it  can  part  with  before  con- 
densation commences. 

Suppose  you  take  a  quantity  of  steam  at  its 
"  natural "  temperature,  and  introduce  it  into  a 
cylinder  cooler  than  itself,  a  considerable  part  of  it 
will  immediately  condense  and  the  pressure  will  fall 
rapidly.  If,  however,  it  is  super-heated,  it  will  not 
begin  to  condense  until  all  the  super-heat  has  gone. 

By  suitable  arrangements  the  super-heat  can  be 
obtained  free,  by  utilizing  heat  which  would  other- 
wise go  to  waste. 

A  super-heater  locomotive  has  in  its  smoke-box  a 
number  of  tubes  through  which  the  steam  passes 
on  its  way  from  the  boiler  to  the  cylinders.  This 
arrangement  of  tubes  is  called  a  "  super-heater," 
and  it  is  so  placed  that  the  hot  gases  after  passing 
through  the  tubes  of  the  boiler  strike  against  it  before 
making  their  way  upwards  to  the  chimney.  Thus 
heat  which  would  otherwise  be  carried  away  into 
the  air  is  imparted  to  the  steam  on  its  way  to  the 
cylinders,  and  so  it  becomes  "  super-heated." 

To  accommodate  the  super-heater  the  smoke-box 
generally  has  to  be  enlarged  a  little,  with  the  result 
that  a  "  super-heater  "  locomotive  can  usually  be 
recognized  from  the  fact  that  its  smoke-box  is 
obviously  longer  than  is  generally  the  case. 

While    on   the    subject    of   condensation   another 
little  point  may  be  mentioned  here,  although  it  is 
F  81 


COMPOUND  LOCOMOTIVES 

not  strictly  connected  with  the  subject  of  this 
chapter.  At  starting,  when  the  cylinders  are  com- 
paratively cool,  there  is  a  great  tendency  for  some 
of  the  steam  to  condense  in  the  cylinders,  and  if  it 
were  to  be  allowed  to  accumulate  it  might  have  very 
disastrous  effects.  Water  is  only  compressible  to  a 
very  slight  extent,  so  that  if  there  were  more  water 
in  a  cylinder  than  would  fill  the  small  space  between 
the  end  of  the  cylinder  and  the  furthest  point  in 
the  travel  of  the  piston  something  would  have  to 
"  go."  In  all  probability  the  cylinder-cover  would 
be  knocked  right  off  and  one  end  of  the  cylinder 
left  quite  open. 

To  prevent  this  there  is  at  each  end  of  the  cylinder 
a  small  tap,  called  a  "  drain-cock."  These  can  be 
operated  from  the  cab  by  a  system  of  levers,  and 
when  he  has  reason  to  think  that  water  is  collecting 
the  driver  opens  these  and  the  steam  blows  it  out. 
That  is  the  cause  of  the  familiar  escape  of  steam 
under  the  engine  and  the  harsh  hissing  sound  which 
accompanies  it. 

But  to  return  to  our  subject ;  even  when  the 
steam  is  super-heated  it  cannot  be  used  expansively 
in  one  cylinder  beyond  a  certain  extent.  Therefore, 
it  is  in  some  cases  led  to  a  second  cylinder  of  larger 
dimensions  than  the  first. 

Probably  the  question  will  at  once  arise  in  the 
readers  mind,  "  Why  must  it  be  larger  ?  "  Because, 
in  order  to  obtain  the  expansive  force  from  the 
steam  we  must  give  it  a  chance  to  expand,  and  it 
can  only  expand  if  we  introduce  it  into  a  cylinder 
which  is  larger  than  the  one  it  is  leaving. 

82 


COMPOUND  LOCOMOTIVES 

Or  we  may  look  at  it  another  way.  Imagine  the 
first  or  "  high-pressure  "  cylinder  to  be  full  of  steam 
at,  say,  50  Ibs.  pressure.  We  connect  it  to  the  "low- 
pressure  "  cylinder  into  which  it  flows.  The  low- 
pressure  cylinder,  let  us  suppose,  is  twice  the  diameter 
of  the  high-pressure,  and  so  as  the  steam  enters  it 
expands  and  its  pressure  falls,  until  at  the  end  of 
the  stroke  it  is  only  25  Ibs.  The  average  pressure  in 
the  low-pressure  cylinder  throughout  the  stroke  will 
be  somewhere  about  40  Ibs. 

Now  you  must  remember  that  the  two  pistons, 
the  one  in  the  high-pressure  cylinder  and  the  one 
in  the  low-pressure  cylinder,  are  mechanically  con- 
nected, so  that  they  move  together.  The  high- 
pressure  piston  thus  pushes  the  "  old  "  steam  out 
of  its  cylinder,  and  the  same  steam  in  its  turn  pushes 
the  low-pressure  piston.  The  high-pressure  piston 
has  to  exert  a  pressure  of  (on  the  average)  40  Ibs. 
on  every  square  inch  in  order  to  push  the  old  steam 
out,  but  because  of  its  expansion  that  same  steam 
pushes  with  that  same  pressure  per  square  inch  upon 
the  much  larger  low-pressure  piston.  If  the  area 
of  the  high-pressure  piston  were  100  square  inches 
and  that  of  the  low-pressure  200  square  inches,  the 
old  steam  would  push  back  upon  the  high-pressure 
piston  to  the  extent  of  4000  Ibs.,  but  forward  upon 
the  low-pressure  to  the  extent  of  8000  Ibs.,  giving 
a  net  gain  to  the  engine  of  4000  Ibs. 

One  of  the  earliest  of  the  compound  locomotives 
was  a  type  of  engine  made  and  used  by  the  North- 
Eastern  Railway  which  had  two  cylinders,  one  high- 
pressure  and  one  low-pressure.  These  were  placed 

83 


COMPOUND  LOCOMOTIVES 

one  on  each  side  of  the  engine,  just  as  are  the  two 
cylinders  of  the  ordinary  "  simple  "  engine.  Had 
not  some  provision  been  made  for  starting  this 
would  have  meant  that  the  engine  would  have 
started  with  one  cylinder  only,  for  obviously  the 
low-pressure  cylinder  cannot  come  into  operation 
till  the  engine  has  moved.  To  overcome  this  diffi- 
culty the  steam  pipes  were  so  arranged  that  to  start 
the  engine  steam  passed  straight  from  the  boiler 
to  both  cylinders,  so  that  it  started  as  a  "  simple  " 
engine.  Then,  when  speed  had  been  attained,  the 
operation  of  certain  valves  caused  it  to  change  into 
"  compound." 

The  London  and  North-Western  Railway,  also, 
were  pioneers  with  a  famous  type  of  compound 
engine  in  which  there  were  two  high-pressure 
cylinders,  one  on  each  side  of  the  engine,  and  one 
very  large  low-pressure  cylinder  in  the  centre,  between 
the  other  two.  The  two  high-pressure  cylinders 
drove  one  pair  of  driving  wheels  and  the  low-pressure 
cylinder  the  other  pair,  the  two  pairs  being  coupled 
together  with  side-rods. 

Several  British  lines  have  had  some  compound 
engines  at  work  for  a  number  of  years,  and  so  have 
some  of  the  United  States  railways. 

One  reason  why  the  compound  arrangement  is 
not  more  generally  employed  is  the  oft-mentioned 
trouble  of  the  limitation  of  size.  To  get  the  best 
result  much  more  space  would  be  needed  than  is 
available  upon  a  locomotive. 

A  second  reason  is  the  variability  of  the  load, 
which  is  at  times  six  or  eight  times  as  great  as  at 

84 


COMPOUND  LOCOMOTIVES 

others.  On  ships  and  in  large  factories,  where  the 
load  is  fairly  steady,  steam  engines  are  almost 
always  "  compound  "  or  else  "  triple-expansion  " 
(the  steam  passing  through  three  cylinders  in  suc- 
cession), but  in  the  case  of  locomotives  there  are 
only  certain  services,  where  the  demand  upon  the 
engine  is  fairly  steady,  where  "  compound  "  engines 
show  to  advantage.  In  other  cases  the  less  costly 
and  less  complicated  "  simple  "  engines  will  probably 
continue  to  hold  the  field. 

Indeed,  the  question  of  "  compound  versus  simple  " 
is  such  a  doubtful  one  that  the  building  of  compound 
engines  is  very  largely  a  matter  of  the  personal  views 
of  the  gentleman  who  at  the  moment  happens  to 
hold  the  office  of  Chief  Mechanical  Engineer  on 
each  line. 


CHAPTER  VI 
OIL-DRIVEN  LOCOMOTIVES 

FOR  industrial  purposes  the  oil  engine  has  made 
a  great  place  for  itself  and  is  a  very  serious 
competitor  of  the  steam  engine. 

In  factories  and  electric  generating  stations  oil- 
driven  engines  are  to  be  found  in  large  and  increasing 
numbers,  while  for  road  vehicles  the  engine  worked 
by  a  light  oil  is  supreme.  The  conditions  which 
prevail,  however,  on  a  railway  have  so  far  left  the 
steam  engine  in  undisputed  sway. 

The  reasons  for  this  are  various.  For  one  thing, 
the  load  changes  in  a  manner  not  to  be  met  with  in 
a  factory.  For  another,  the  locomotive  has  to  be 
ready  to  stop  and  stait  pgain  at  any  moment,  whereas 
in  a  factory  the  machinery  runs  for  hours  at  a  stretch. 
Again,  a  railway  engine  must  be  as  near  absolute 
reliability  as  is  possible. 

Now  the  internal-combustion  engine  driven  by  oil 
is  a  very  wonderful  machine,  for  economy  far  to  be 
preferred  to  a  steam  engine,  but  it  has  not  the  same 
reliability  and  it  is  difficult  to  see  how  it  ever  can 
have.  A  steam  engine,  in  bad  condition  even,  will 
work.  It  may  work  badly,  but  it  will  go  on  doing 
its  best  until  it  drops  to  pieces.  There  is  a  steam 
engine  in  London  driving  a  factory,  which  has  been 

86 


OIL-DRIVEN  LOCOMOTIVES 

doing  the  same  thing  since  before  the  internal- 
combustion  engine  was  first  invented.  The  whole 
history  of  the  gas,  oil  and  petrol  engine,  from  its 
crude  beginning  up  to  the  present  time,  is  covered 
by  the  working  life  of  that  single  steam  engine. 
True,  it  is  not  very  efficient,  but  it  works  and  the 
owners  of  the  factory  know  that  they  can  rely  upon 
it  to  keep  the  factory  going. 

Nor  is  that  an  exceptional  case  ;  it  is  simply  due 
to  the  inherent  simplicity  of  the  steam  engine,  a 
simplicity  which  applies  both  to  its  construction 
and  to  its  mode  of  action. 

Against  this,  consider  the  short  life  of  the  motor- 
car engine  and  the  fact  that  even  the  best  motor-car 
engine,  good  though  it  is,  has  its  occasional  bad 
periods  when  it  is  reluctant  to  start,  or  pulls  badly. 

Moreover,  internal-combustion  engines  will  only 
work  at  a  comparatively  high  speed,  whereas  a  steam 
engine  will  work  at  any  speed  down  to  a  "  crawl." 
In  the  motor  vehicle  this  difficulty  is  mitigated  by 
the  use  of  gearing  and  in  other  ways,  but  those 
devices  cannot  be  applied  practically  where  such 
heavy  power  has  to  be  applied  as  in  the  railway 
engine. 

Then  there  is  the  reversing.  A  steam  engine 
reverses  quite  easily.  The  same  cannot  be  said  of  the 
internal-combustion  engine. 

There  was  an  engine  made  some  years  ago  in  which 
it  was  attempted  to  utilize  a  steam  turbine  and  so 
to  take  advantage  of  the  superior  efficiency  of  the 
turbine  when  compared  with  the  ordinary  recipro- 
cating steam  engine.  But  the  turbine  suffers  from 

87 


OIL-DRIVEN  LOCOMOTIVES 

the  same  troubles  as  the  internal-combustion  engine, 
in  that  it  only  works  well  at  a  high  speed  and  cannot 
be  reversed  easily.  It  was,  therefore,  sought  to 
overcome  this  by  electrical  means,  and  the  turbine 
was  made  to  drive  a  dynamo  at  a  constant  speed 
and  always  in  the  same  direction  ;  while  the  current 
from  the  dynamo  was  led  to  motors  which  drove  the 
wheels.  The  motors  could,  of  course,  be  controlled 
as  to  speed  and  direction  as  they  are  controlled  in 
every  electric  train  or  tramcar. 

The  electric  machinery,  it  will  be  noticed,  generated 
no  power  at  all,  as  indeed  it  never  does,  but  simply 
transmitted  the  power  from  the  turbine  to  the  wheels, 
and  its  only  reason  for  being  there  at  all  was  to 
enable  the  speed  and  direction  to  be  controlled. 

This  engine  did  not  prove  a  marked  success,  and 
there  is  little  reason  to  expect  that  any  more  will  be 
built  on  those  lines.  The  same  method  of  trans- 
mission is  applicable  in  connection  with  an  internal- 
combustion  oil  engine,  but  there  are  many  diffi- 
culties in  the  way  of  success. 

At  the  same  time  there  are  many  reasons  why  oil 
would  make  an  ideal  fuel  for  railway  engines.  For 
one  thing,  it  is  so  clean  and  easily  handled.  Instead 
of  the  labour  of  shovelling  coal  or  tipping  it  into 
the  tender  the  oil  can  be  pumped  in  with  no  trouble 
and  no  dust  in  a  small  fraction  of  the  time.  The 
fireman,  too,  on  a  coal-fired  locomotive  has  to  shovel 
many  hundredweights  of  coal  per  trip.  With  oil 
he  has  nothing  to  do  but  see  to  the  adjustment 
of  two  valves,  the  rest  of  his  energies  being  available 
to  assist  the  driver. 

88 


^  5; 


OIL-DRIVEN  LOCOMOTIVES 

The  only  solution  of  the  difficulty,  therefore,  seems 
to  be  to  burn  oil  instead  of  coal  in  the  fire-box  of  a 
steam  locomotive,  and  this  was  actually  done  in 
an  experimental  way  for  twenty  or  more  years 
until  at  last  oil  obtained  a  definite  place  as  a  fuel 
for  railway  steam  engines. 

The  problem  is  how  to  introduce  the  oil  so  that  it 
shall  burn  well  and  economically.  The  obvious  way 
is  to  blow  it  through  a  fine  nozzle  or  series  of  nozzles, 
so  that  it  shall  enter  the  fire-box  in  a  fine  spray. 
In  the  earliest  experiments  the  oil  was  made  to 
combine  with  a  jet  of  steam  in  an  arrangement  of 
nozzles  rather  like  the  "  injector "  by  which  the 
water  is  driven  into  the  boiler.  At  first  sight  it 
would  appear  that  the  mixture  of  steam  with  the 
oil  vapour  would  prevent  it  from  burning  or,  at  all 
events,  damp  down  the  combustion,  but  experience 
has  shown  that  such  is  not  the  case.  The  steam, 
in  the  hot  fire-box,  is  probably  split  up  into  oxygen 
and  hydrogen,  the  hydrogen  acting  as  additional 
fuel  and  the  oxygen,  being  well  mingled  with  it, 
helping  to  promote  a  good  combustion  of  the  oil. 

It  was  the  custom,  too,  in  the  early  trials,  to  use 
oil  merely  as  an  addition  to  the  coal,  some  of  which 
was  still  used.  The  coal  fire  burnt  upon  the  fire- 
bars which  form  the  floor  of  the  fire-box  in  the  usual 
way,  while  the  steam  and  oil  spray  played  upon  it 
from  above. 

The  burning  of  oil  made  little  progress,  however — 
surprisingly  little — for  many  years,  until  necessity, 
the  proverbial  "  mother  of  invention,"  took  a  hand 
in  the  game. 

89 


OIL-DRIVEN  LOCOMOTIVES 

It  came  about  in  this  way.  During  the  war,  in 
Mesopotamia,  there  was  a  scarcity  of  any  kind  of 
fuel  except  oil.  The  locomotives  which  were  being 
used  by  the  British  Army  were  arranged  to  burn 
other  kinds  of  fuel,  and  so  it  became  a  matter  of  great 
urgency  to  devise  some  arrangement  for  burning  oil. 

Now  the  great  obstacle  till  then,  to  the  use  of 
oil,  had  been  the  idea  that  the  oil  must  be  sprayed 
through  fine  nozzles  with  all  the  attendant  risks 
that  the  nozzles,  because  of  their  fineness,  would 
frequently  choke. 

The  petrol  used  in  motor-car  engines  has  to  pass 
through  fine  holes,  and  every  motorist  knows  from 
sad  experience  how  liable  these  are  to  be  choked 
with  particles  of  grit,  no  matter  how  careful  he  may 
be.  With  the  cruder  oil  used  to  fire  a  locomotive 
this  risk  would  be  much  greater. 

So  there  was  a  dilemma ;  the  only  fuel  available  was 
oil,  and  oil  as  employed  till  then  was  not  reliable. 

Fortunately  the  responsible  man,  Colonel  F.  R. 
Macdonald,  was  a  man  of  resource,  and  he  was  not 
only  able  to  avoid  the  dilemma  which  faced  him 
there,  but  he  provided  at  the  same  time  a  method 
of  burning  oil  which  has  been  of  great  value  since 
in  all  parts  of  the  world. 

To  understand  the  beautiful  simplicity  and  effec- 
tiveness of  this  invention,  it  is  necessary  just  to 
think  what  are  the  points  to  be  attained.  First  the 
oil  has  to  be  "  atomized,"  that  is  to  say,  reduced  to 
the  finest  possible  particles.  It  cannot,  of  course, 
be  actually  reduced  to  single  "  atoms  "  as  the  term 
suggests,  but  it  must  be  changed  into  drops  of  the 

90 


OIL-DRIVEN  LOCOMOTIVES 

smallest  practical  dimensions.  The  second  point  is 
that  the  apparatus  must  be  free  from  fine  nozzles 
or  anything  else  which  would  be  liable  to  become 
choked  or  otherwise  put  out  of  action.  It  must  be 
something  which  cannot  go  wrong. 

We  can  now  see  how  Colonel  Macdonald's  "  burner  " 
fulfils  these  two  conditions. 

To  commence  with,  imagine  a  piece  of  iron  pipe 
with  a  bore  of  a  quarter  of  an  inch  or  so,  quite  open  at 
the  end  through  which  the  oil  is  free  to  trickle.  It  is 
humanly  impossible  for  such  a  thing  to  become  choked. 

As  it  drips  from  the  end  of  this  tube  the  oil  falls 
upon  what  might  best  be  described,  perhaps,  as  a 
kind  of  flat  shovel. 

Probably  every  reader  has  noticed  the  shovel  with 
which  the  cashier  at  the  bank  handles  large  quantities 
of  coins. 

Let  the  tube  just  described  take  the  place  of  the 
handle  of  such  a  shovel ;  then  turn  up  the  front  edge  a 
little  and  cut  a  number  of  notches  in  the  ridge  so 
formed.  You  now  have  a  fairly  good  idea  of  the  burner. 

Oil  from  the  tube  flows  on  to  the  flat  bottom  of  the 
shovel,  distributes  itself  fairly  thereon  and  then 
proceeds  to  drip  out  through  the  notches.  Thus 
there  falls  from  the  front  edge  of  the  shovel  a  little 
curtain  of  dripping  oil.  The  shovel  is  4  ins.  wide,  and 
so  the  curtain  is  4  ins.  wide,  too.  The  notched  edge  over 
which  the  oil  falls  is  appropriately  termed  the  "weir." 

Now  just  underneath  the  shovel  is  a  very  fine 
slit,  also  4  ins.  long,  through  which  steam  blows 
in  horizontally,  so  that  the  vertical  curtain  of  oil 
drops,  as  it  were,  upon  a  horizontal  ribbon  of  steam. 

91 


OIL-DRIVEN  LOCOMOTIVES 

It  is  hardly  necessary  to  point  out  how  the  steam 
will  carry  the  oil  forward,  at  the  same  time  breaking 
it  up  into  fine  spray.  Thus  the  combined  jet  of  steam 
and  oil  enters  the  fire-box  of  the  engine.  There  it 
encounters  a  certain  amount  of  air  and  bursts  into 
flame. 

No  fuel  is  used,  in  this  system,  except  the  oil. 
The  fire-bars  are  entirely  removed,  the  ash  pan, 
which  usually  occupies  a  place  just  under  the  bars 
and  catches  the  ashes  which  fall  between  them, 
disappears  too.  Instead,  the  fire-box  is  fitted  with 
a  special  floor  of  iron  on  which  is  placed  a  layer  of 
fire-brick.  Several  fire-brick  arches,  too,  are  built 
in  the  fire-box  for  a  purpose  which  will  be  apparent 
in  a  moment. 

In  the  earlier  oil-burning  systems  the  burner  or 
jet  was  introduced  from  the  rear  of  the  fire-box 
near  the  door  through  which  the  fireman  usually 
throws  in  the  coal.  With  this  system,  however,  a 
totally  different  plan  is  adopted.  The  burner  is  in 
the  front  of  the  fire-box  underneath  the  boiler.  The 
jet  enters  underneath  a  small  brick  arch  where  it 
bursts  into  flame.  But  for  the  arch  the  heat  would 
be  drawn  straight  up  and  through  the  tubes,  but 
it  is  more  economical  to  make  it  play  first  round 
the  fire-box,  so  the  arch  is  introduced.  Consequently 
the  flame  is  projected  towards  the  rear  of  the  fire- 
box, at  which  point  more  air  is  met,  which  air,  having 
entered  through  channels  in  the  brick  floor,  is  already 
heated  by  heat  which  would  otherwise  have  been 
lost.  The  flames  then  encounter  another  arch  which 
throws  them  backward  and  upward,  where  yet 

92 


OIL-DRIVEN  LOCOMOTIVES 

another  arch  is  met  with,  and  the  result  is  a  swirling 
action  on  the  part  of  the  flames  which  ensures  perfect 
combustion  and  an  economical  distribution  of  the 
heat  before  the  hot  gases  finally  pass  through  the 
tubes  and  up  the  chimney. 

The  fire  is  lit  in  a  most  simple  manner.  A  handful 
of  oily  cotton  waste  is  lit  and  thrown  into  the  fire- 
box ;  then  the  steam  and  oil  are  turned  on  and 
instantly  there  is  a  hot  fire.  One  difficulty  presents 
itself  at  this  point,  namely,  that  when  the  engine  is 
cold  there  is  no  steam  to  be  got  from  it.  Hence  at 
starting  a  temporary  supply  has  to  be  brought  by 
means  of  a  flexible  pipe  from  some  other  source. 
That  can  easily  be  arranged  for,  however,  at  every 
engine  shed. 

The  supply  of  oil  and  the  supply  of  steam  can  both 
be  controlled  by  means  of  simple  valves  in  the  cab 
of  the  engine,  so  that  the  flame  is  at  all  times  under 
perfect  control  from  the  cab. 

Should  this  book  fall  into  the  hands  of  anyone 
who  was  in  Mesopotamia  he  will  probably  remember 
the  most  objectionable  little  insect  met  with  out 
there  which  rejoices  in  the  name  of  "  Scarab."  The 
"  scarab  "  seems  to  be  an  exceedingly  well-designed 
and  efficient  little  beast,  which  is  exceedingly  diffi- 
cult to  kill.  His  construction  is  such  that  he  is 
apparently  in  working  order  at  all  times  and  under 
the  most  adverse  conditions.  Hence  Colonel  Mac- 
donald  conceived  the  happy  idea  of  calling  his  oil- 
burner  the  "  scarab,"  indicating  that  it  possesses 
those  excellent  qualities  of  strength  and  reliability 
so  necessary  in  connection  with  a  locomotive. 

93 


CHAPTER  VII 
BRAKES :  HOW  THEY  WORK 

THE  story  of  the  railways  is  largely  one  of 
safeguards.  The  lessons  of  experience  have 
been  applied  regardless  of  cost  in  order  to 
make  railways  safe  for  those  who  travel  by  them. 

And  one  of  the  most  important  of  these  is  the 
"  continuous  brake."  Why  "  continuous  "  ?  you 
may  ask.  Think  a  moment. 

A  train  is  rushing  along  at  fifty  or  sixty  miles  an 
hour,  and  for  some  reason  or  other  is  suddenly  called 
upon  to  stop.  Suppose  that  under  such  conditions 
only  the  engine  had  a  brake.  The  speed  of  the 
locomotive  would  by  the  application  of  this  be 
suddenly  checked,  but  the  vehicles  behind,  because 
of  their  great  momentum,  would  come  pressing  on. 
At  the  best,  they  would  push  the  engine  and  so 
prevent  it  from  stopping  in  so  short  a  space  as  it 
could  easily  do  if  it  were  by  itself.  At  the  wrorst,  the 
hinder  ones,  by  pushing  the  front  ones  against  the 
engine,  might  actually  force  them  off  the  line  long 
before  the  speed  had  been  materially  reduced, 
resulting  in  a  serious  accident.  In  between  these 
two  extremes  there  are  a  vast  range  of  possibilities, 
all  of  them  more  or  less  unpleasant  for  the  traveller. 

The  result  is  that  all  fast-moving  trains  are  now 

94 


BRAKES :   HOW  THEY  WORK 

fitted  with  some  form  of  continuous  brake,  by  means 
of  which  the  driver,  or  in  an  emergency  the  guard, 
or  even  a  piece  of  automatic  signalling  apparatus, 
can  apply  the  brake  quickly  to  every  vehicle  in  the 
train. 

Another  advantage  of  the  continuous  brake  is 
this.  It  can  be  easily,  and,  in  fact,  always  is,  so 
arranged  that  it  applies  itself  automatically  in  the 
event  of  certain  things  happening.  For  instance, 
one  of  the  dangers  of  railway  working  is  that  a 


normal  direction 
of    traffic 


Fig.  4. — DIAGRAM  SHOWING  HOW  CATCH -POINTS  ABE  MADE, 

IN    ORDER   TO    CATCH    RUNAWAY   WAGONS. 

A  train  passing  from  A  to  B  will  set  the  points  for  itself, 
but  should  anything  break  away  and  run  back — from  B  to- 
wards A — the  catch-points  will  throw  it  off  the  line,  thereby 
preventing  it  injuring  anything  else. 

coupling  may  break  and  a  portion  of  a  train  be  left 
behind.  Now  should  that  occur  in  ascending  an 
incline,  the  hind  portion  of  the  train  would  almost 
certainly  run  back  of  its  own  accord,  probably 
dashing  into  something  before  it  had  gone  far.  A 
runaway  train  of  that  sort  ignores  signals,  and  the 
only  thing  that  can  be  done  with  it  is  to  turn  it  into 
a  siding  where  it  can  expend  its  stored- up  energy 
in  demolishing  a  buffer-stop  or  something  of  that 
^sort.  In  many  cases  there  are  placed  at  the  foot 
of  inclines  what  are  called  "  catch  points  "  for  this 

95 


BRAKES :   HOW  THEY  WORK 

very  purpose.  They  are  like  ordinary  points,  except 
that  they  are  not  controlled  by  rods,  but  by  springs. 
A  train  passing  through  "  catch  points "  in  the 
normal  direction,  simply  pushes  them  into  the  right 
position  for  itself  as  it  passes  over,  but  as  soon  as 
it  has  passed  the  springs  re-set  them  so  that  if  the 
train  were  to  run  back  it  would  be  turned  into  a 
siding  or  short  length  of  line.  In  either  case,  if  it 
came  with  any  speed,  it  would  be  wrecked,  but  the 
catch  points  would  at  all  events  save  other  trains 
from  being  wrecked  by  it. 

Catch  points  and  similar  devices  are  employed  to 
catch  and  turn  aside  runaway  goods  wagons,  but 
passenger  vehicles  are  dealt  with  by  the  automatic 
brake. 

It  stands  to  reason  that  in  order  to  control  the 
brakes  on  every  vehicle  there  must  be  something  or 
other  which  runs  the  whole  length  of  the  train,  and 
it  is  arranged  that  the  severance  of  that  something 
should  put  the  brake  on. 

The  "  something  "  is,  in  fact,  a  pipe,  known  as 
the  "  train  pipe,"  and  the  motive  power  by  which 
the  brakes  are  worked  is  in  some  cases  compressed 
air  and  in  others  the  precise  opposite,  a  "  vacuum." 
Some  railways  prefer  one  system,  some  the  other, 
while  many  of  them  have  stock  fitted  with  both  so 
that  they  can  work  over  lines  where  either  system 
prevails. 

Let  us  take  first  the  automatic  vacuum  brake. 
Under  each  vehicle  there  is  a  cylinder  with  a  piston 
in  it  and  a  piston  rod  projecting  through  the  cover 
by  which  the  motion  of  the  piston  is  communicated 

96 


CAB  INDICATOR. 

This  represents  one  part  of  an  apparatus  for  indicating  in  the  cab  of  a  locomotive 
the  state  of  the  signals  which  it  passes.  This  part  is  fixed  to  the  engine  ;  near  the 
signal  is  an  inclined  plane  with  which  this  comes  into  contact  as  it  moves  over. 

There  are  several  types  of  this  apparatus,  this  particular  one  being  the  invention  of 
Messrs.  Sykes,  of  Clapham,  London. 


BRAKES :   HOW  THEY  WORK 

to   the   outside.      The   position   of  the   cylinder   is 
vertical  with  the  piston  rod  projecting  downwards. 

These  cylinders  are  not  very  high  because  of  the 
limited  space  in  which  they  have  to  be  fixed,  under- 


to  tram 
pipe. 

Fig.  5. — DIAGRAM  SHOWING  HOW  THE  VACUUM  BRAKE  WORKS. 
(N.B. — For  the  sake  of  simplicity  the  piston-rod  is  not  shown.) 

(1)  When  the  air  is  sucked  out  the  ball  lifts,  and  the  air  is 
drawn  from  above  the  piston  as  well  as  from  below. 

(2)  When  air  is  admitted  the  ball  prevents  it  reaching  the 
upper  side  of  the  piston ;  therefore  the  piston  is  forced  upwards. 

neath  the  vehicle,  but  they  are  of  large  diameter,  the 
largest  being  as  much  as  21  ins. 

Connected  with  the  cylinder  there  is  a  vacuum 

reservoir.     In  some  cases  this  is  formed  by  a  steel 

envelope  which  surrounds  the   cylinder  itself.     In 

other  cases  it  is  a  separate  vessel  joined  to  the  cylinder 

G  97 


BRAKES :   HOW  THEY  WORK 

by  means  of  a  pipe.  In  either  case  it  is  always  in 
communication  with  the  upper  part  of  the  cylinder, 
above  the  piston. 

Either  embodied  in  the  piston  itself  or  else  in  the 
piston  rod  there  is  a  valve  of  the  kind  known  as 
"  non-return,"  meaning  that  air  can  pass  freely 
through  it  in  one  direction,  but  cannot  return.  It 
consists  generally  of  a  metal  ball  held  in  a  little 
chamber,  in  the  floor  of  which  is  a  hole.  The  area 
just  round  the  hole  forms  what  is  termed  the  "  seat- 
ing "  for  the  ball,  and  the  action  is  that  air  coming 
up  through  the  hole  raises  the  ball  easily  and  passes 
by  it,  while  should  it  attempt  to  return  the  ball 
covers  the  hole  and  the  harder  the  air  presses  back 
the  more  firmly  is  the  ball  held  down  upon  the 
seating. 

The  under  part  of  the  cylinder,  below  the  piston, 
is  in  communication  with  the  train  pipe,  one  end  of 
which,  of  course,  terminates  upon  the  engine. 

We  can  now  see  how  the  whole  apparatus  works. 
The  driver,  by  means  of  an  "  ejector,"  which  will 
be  described  later,  is  able  to  withdraw  air  from  the 
train  pipe,  thereby  causing  the  air  to  be  sucked  also 
from  the  cylinders.  The  ball  valves,  under  these 
conditions,  are  open,  allowing  the  air  to  be  drawn 
out  freely,  with  the  result  that  the  whole  apparatus 
is  exhausted  of  air.  Pipes,  cylinders,  vacuum 
reservoirs,  all  are  freed  from  air,  and  in  those  cir- 
cumstances the  piston  falls  down  to  the  bottom  of 
the  cylinder  and  the  brake  is  "  off." 

Now  suppose  that  the  driver  lets  air  into  the  train 
pipe.  It  rushes  along,  flooding  the  lower  part  of 

98 


BRAKES :   HOW  THEY  WORK 

cylinder  after  cylinder  ;  the  ball  valves  coming  into 
operation  prevent  the  air  from  passing  the  pistons, 
and  the  whole  pressure  of  the  atmosphere,  about 
15  Ibs.  on  every  square  inch,  acting  upon  each  piston 
forces  it  upwards,  draws  up  the  piston  rod  and 
operates  the  system  of  rods  and  levers  by  which  the 
brake  blocks  are  applied  to  the  wheels. 

Release   pipe 


fig.  6. — DIAGRAM  SHOWING  HOW  THE  VACUUM  BRAKE 

WORKS    ON    AN    ELECTRIC    VEHICLE. 

The  air  pump,  acting  through  the  release  pipe,  always  keeps 
up  a  good  vacuum  in  the  release  reservoir.  When  the  driver 
wants  to  release  the  brake  he  opens  the  release  valve  (by 
electricity),  and  the  brake  is  released  almost  instantly. 

It  may  seem  strange,  but  this  action  requires  quite 
an  appreciable  time  to  take  effect  along  a  long  train. 
It  might  be  as  long  as  half  a  minute  after  the 
driver  had  opened  his  valve  before  the  brakes  went 
on  on  the  last  vehicle,  so  some  special  provision  has 
to  be  made  to  speed  things  up.  This  is  called  the 
accelerator  valve.  One  is  fixed  in  the  train  pipe 
near  each  cylinder  and  its  action  is  this.  As  soon 
as  air  begins  to  reach  the  accelerator,  and  the  vacuum 
begins  to  fall,  this  valve  opens  and  lets  air  freely 
into  the  pipe,  thereby  hastening  the  action  not  only 

99 


BRAKES  :   HOW  THEY  WORK 

of  the  cylinder  adjacent,  but  also  the  accelerator  and 
cylinder  of  the  next  vehicle.  In  effect,  the  result  is 
that  instead  of  all  the  air  required  to  apply  the  brakes 
having  to  travel  right  along  from  the  engine,  through 
many  feet  of  pipe,  entrances  are  formed  for  the 
air  on  each  vehicle.  As  soon  as  they  have  done 
their  work  the  accelerator  valves  close  automatically 
and  remain  closed  until  they  are  required  again. 

The  train  pipe  consists  of  metal  tubing  upon  the 
vehicles,  with  flexible  ends,  each  end  being  fitted 
with  a  cleverly  designed  union  by  which  it  can  be 
quickly  and  securely  attached  to  the  flexible  pipe 
of  the  next  vehicle.  Most  travellers  have  at  some 
time  or  other  watched  the  operation  of  coupling 
and  uncoupling  these  flexible  pipes. 

Now  supposing  a  coupling  were  to  break  and  a 
part  of  a  train  thereby  became  detached  from  the 
part  in  front  of  it,  the  flexible  pipe  would  of  necessity 
be  torn  in  two  also.  Its  open  ends  would  then 
admit  air  and  the  brake  would  be  applied  with  the 
maximum  of  force  to  both  portions.  The  driver 
would  know  that  something  had  happened  and  the 
rear  portion,  no  matter  if  it  were  on  a  steep  incline, 
could  not  run  away  backwards. 

Reference  has  been  made  elsewhere  to  the  injector, 
by  means  of  which  a  jet  of  steam  throws  water  into 
the  boiler.  The  "  ejector,"  by  which  the  air  is  drawn 
out  of  the  train  pipe  and  the  vacuum  created,  is  the 
same  thing  working  the  opposite  way.  Instead  of 
throwing  something  in,  it  throws  something  out ; 
its  very  name  signifies  that.  It  consists  of  an  arrange- 
ment of  nozzles  through  one  of  which  steam  blows 

100 


BRAKES:   HOW  THEY  WOUK 

in  such  a  way  that  it  carries  the  air  along  with  it. 
This  has  to  be  kept  going  almost  continuously,  in 
order  to  maintain  the  vacuum  in  spite  of  the  numerous 
little  leaks  which  it  is  impossible  to  prevent. 

It  will  be  noticed  that  only  the  engine  can  release 
the  brake  off  a  vehicle  fitted  with  the  vacuum  brake, 
and  the  point  will  at  once  suggest  itself  that  very 
awkward  conditions  would  arise  if  an  odd  coach 
needed  to  be  moved  a  short  distance  by  man  power 
or  by  a  horse.  The  brakes  would  be  on  and  there 
might  be  no  engine  at  hand  to  release  them. 

This  is  provided  against  by  very  simple  means. 
Underneath  a  coach  fitted  for  the  vacuum  brake, 
usually  about  the  middle  of  its  length,  there  will  be 
noticed  a  loose  wire.  There  is  sometimes  an  arrow 
painted  upon  the  frame  of  the  coach  to  call  attention 
to  the  position  of  it. 

It  is  only  necessary  to  pull  this  wire  in  order  to 
release  the  brake.  What  it  does  is  to  operate  a  little 
valve  which  lets  air  into  the  cylinder  above  the 
piston,  destroying  the  vacuum  entirely  and  leaving 
the  brake  free.  When  the  vehicle  is  coupled  up 
once  more  and  the  air  exhausted  by  the  engine  the 
brake  acts  just  the  same  as  before. 

What  has  been  said  so  far  applies  to  the  use  of 
the  vacuum  brake  on  steam  trains ;  when  applied 
to  electric  trains  certain  modifications  are  necessary. 

In  the  first  place  an  exhauster  or  air-pump  driven 
by  an  electric  motor  has  to  take  the  place  of  the 
ejector.  Then,  again,  special  provision  has  to  be 
made  for  the  rapid  release  of  the  brakes.  An  essential 
feature  of  the  electric  propulsion  of  trains  is  the 

101 


BRAKES:   HOW  THEY  WORK 

quickness  with  which  they  can  re-start.  Anyone 
who  has  watched  the  rapid  succession  of  trains 
pouring  through  a  station  on  one  of  the  London 
Underground  lines,  for  example,  at  a  busy  time  of 
the  day,  will  realize  what  this  means.  Yet  to  create 
a  vacuum,  from  the  very  nature  of  things,  takes 
time,  so  that  the  same  arrangement  which  supplies 
perfectly  the  needs  of  a  steam  train  might  be  too 
slow  in  its  action  for  an  electric  train. 

To  meet  this  difficulty  there  is  a  second  pipe 
running  the  whole  length  of  the  train  called  the 
release  pipe,  and  connected  to  it  at  various  points 
are  large  vessels  which  form  vacuum  reservoirs,  and 
which  are  called  "  releasing  reservoirs." 

At  intervals  the  release  pipe  is  connected  to  the 
train  pipe  by  means  of  connecting  pipes,  in  each  of 
which  there  is  inserted  a  valve  called  a  "  release 
valve."  Now  this  valve  is  operated  by  electricity,  and 
the  purpose  of  it  is  to  hasten  the  release  of  the  brakes. 

The  brakes  are  applied  in  the  ordinary  way,  by 
the  opening  of  a  valve  in  the  driver's  cabin.  To 
release  them  the  driver  closes  this  valve  again,  and 
the  exhauster,  which  runs  continuously,  then  begins 
to  restore  the  vacuum.  At  the  same  time  an  electric 
current  opens  the  release  valves,  putting  the  train 
pipe  at  several  points  into  communication  with  the 
release  pipe  and  its  release  reservoirs.  The  reservoirs 
therefore  help  the  exhauster  and  the  result  is  a 
quick  release  of  the  brakes.  The  highest  vacuum 
which  is  practically  possible  is  maintained  in  the 
release  pipe  and  reservoirs  to  ensure  the  utmost 
efficiency  frornjthis  arrangement. 

102 


BRAKES :   HOW  THEY  WORK 


We  can  now  turn  to  the  alternative  system,  where 
the  brakes  are  worked  by  compressed  air. 

This  device  is  called  the  Westinghouse  brake, 
after  that  versatile  American  engineer,  George 
Westinghouse,  who  invented  it  about  fifty  years  ago. 

To  commence  at  the  beginning,  there  is  on  the 
engine  a  small  subsidiary  engine  combined  with  an 


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TKAqi  PIPE 

Fig.  7. — DIAGRAM  SHOWING  HOW  THE  WESTINGHOUSE  BRAKE 

IS   ARRANGED    ON   A   GUARD'S   VAN. 

Pressure  in  train  pipe  so  operates  the  triple  valve  that  air 
escapes  from  cylinder,  but  reservoir  is  filled.  Fall  of  pressure 
in  train  pipe  sends  compressed  air  from  reservoir  into  cylinder 
and  applies  the  brake. 

air-pump  for  the  purpose  of  maintaining  a  supply 
of  compressed  air.  This  little  engine  is  familiar  to 
many  because  it  advertises  its  presence  by  working, 
very  often,  when  the  locomotive  is  standing  in  a 
station.  It  is  of  a  type  which  is  very  usual  where 
pumping  is  the  work  required  ;  it  has  no  rotating 
parts,  but  has  simply  two  cylinders,  one  above  the 
other,  a  single  piston  rod  connecting  the  piston 
in  one  cylinder  to  the  piston  in  the  other. 

The   upper   cylinder  is   the   steam   cylinder,    and 

103 


BRAKES :   HOW  THEY  WORK 

its  piston  being  forced  up  and  down  by  the  steam 
moves  the  piston  in  the  air  cylinder  below,  thereby 
pumping  the  air. 

A  very  usual  place  for  this  little  engine  or  com- 
pressor is  on  the  side  of  the  locomotive  just  forward 
of  the  driver's  cab. 

The  air  which  it  pumps  passes  into  the  main 
reservoir  beneath  the  engine,  while  the  steam  which 
drives  it  passes  through  a  valve  controlled  by  the 
pressure  of  the  air,  so  that  the  compressor  works 
automatically.  It  pumps  air  into  the  reservoir 
until  the  pressure  reaches  90  Ibs.  per  square  inch 
and  then  it  stops.  When  the  pressure  falls  appreciably 
it  starts  again  and  raises  it  once  more  to  90  Ibs. 

The  valve  which  does  this  is  beautifully  simple, 
being  little  more  than  a  small  cylinder  with  a  piston 
in  it  which  is  normally  held  up  by  a  spring.  This 
cylinder  is  in  communication  with  the  reservoir, 
and  the  strength  of  the  spring  is  so  adjusted  that  at 
90  Ibs.  the  pressure  of  the  air  just  overcomes  the 
spring,  moves  the  piston  and  thereby  closes  the 
passage  for  the  steam. 

When  the  pressure  falls,  the  spring  raises  the 
piston  again,  opens  the  passage  for  the  steam  and 
sets  the  compressor  going. 

Thus  far,  then,  we  have  a  "  main  reservoir  "  upon 
the  engine,  charged  with  air  to  a  pressure  of  90  Ibs. 
per  square  inch.  There  is  a  passage  from  this  reser- 
voir to  the  "  train  pipe,"  but  the  pressure  there  is 
only  about  70  Ibs.,  so  a  further  valve  is  introduced 
between  the  main  reservoir  and  the  train  pipe  which, 
acting  on  the  same  principle  as  that  just  described, 

104 


Ry  permission  of  th 


\McKenzie,  Holland  &•  Westinghouse  Signal  Co. 
AUTOMATIC  TRAIN  STOP. 


When  the  signal  is  at  danger  the  little  arm  in  the  centre  of  the  picture  stand? 
up  so  that  it  a  train  were  to  pass  it  it  would  strike  the  little  hanging  lever  upon  the 
train.  This  would  put  on  the  brake  and  stop  the  train.  As  soon  as  the  signal  goes 
to  "  safety  "  the  arm  falls  down  so  that  a  passing  train  is  not  affected. 


BRAKES :   HOW  THEY  WORK 

allows  the  air  to  pass  into  the  train  pipe  until  the 
pressure  there  is  70  Ibs.  The  effect  of  this  is  to  make 
quite  sure  that  the  train  pipe  shall  always,  except 
when  it  is  desired  otherwise,  be  fully  charged  with 
air  at  70  Ibs. 

The  air  flows  through  the  train  pipe  right  along 
the  train,  thereby  finding  its  way  into  the  "  auxiliary 
reservoirs,"  of  which  there  is  one  on  every  vehicle, 
generally,  including  the  engine  itself.  The  purpose 
of  the  auxiliary  reservoir  is  to  maintain  a  store  of 
compressed  air  ready  to  apply  the  brake  at  any 
moment.  Note  here  the  precautions  against  the 
possibility  of  failure.  The  compressor,  being  con- 
trolled automatically,  keeps  the  main  reservoir  full 
at  90  Ibs.  The  "  feed  valve  "  again  acting  auto- 
matically, ensures  that  the  train  pipe  shall  be  fed 
from  the  main  reservoir  until  it  is  filled  to  the  pressure 
of  70  Ibs.,  and  from  here  the  air  passes  to  the  auxiliary 
reservoirs,  so  that  close  to  each  spot  where  the 
brakes  may  need  to  be  applied  there  is  a  store  of 
compressed  air,  ready  to  do  the  work. 

On  each  vehicle  there  is  a  cylinder  with  a  piston 
in  it  and  piston  rod  projecting  through  one  end. 
The  normal  position  of  the  piston  is  at  one  end  of 
the  cylinder,  this  being  ensured  by  the  action  of  a 
spring  inside  the  cylinder  which  pushes  the  piston 
to  that  end.  The  admission  of  compressed  air  over- 
comes the  force  of  the  spring  and  moves  the  piston 
to  the  other  end,  thereby  moving  the  rods  and  levers 
which  apply  the  brakes. 

At  first  sight  it  would  seem  to  be  the  simplest  and 
best  thing  just  to  put  the  cylinders  into  communi- 

105 


BRAKES :   HOW  THEY  WORK 

cation  with  the  train  pipe  and  to  force  air  in  when  it 
was  desired  to  put  the  brake  on.  That,  however, 
would  not  be  automatic.  The  severance  of  the  train 
pipe  would  leave  the  brake  "  off."  A  leak  in  the  train 
pipe  or  in  any  part  of  the  apparatus  would  have  the 
same  result,  so  that  the  first  principle  of  railway 
apparatus,  namely,  that  failure  shall  make  for  safety, 
would  be  violated.  The  action  is,  therefore,  reversed 
by  a  very  wonderful  little  valve  called  a  "  triple 
valve,"  which  is  really  the  essential  part  of  the  whole 
apparatus. 

In  this  ingenious  but  simple  contrivance  we  have, 
once  more,  a  little  cylinder  with  a  piston  in  it,  the 
movement  of  which  actuates  a  small  slide  valve  in 
principle  like  the  slide  valve  of  the  locomotive  itself. 

The  cylinder  of  the  triple  valve  is  in  communica- 
tion with  the  train  pipe,  and  so  long  as  the  pressure  in 
the  pipe  is  up  to  the  normal  70  Ibs.  the  piston  is 
held  over  in  its  extreme  position,  under  which  con- 
ditions a  "  port  "  is  open  which  allows  the  air  to 
pass  into  the  auxiliary  reservoir,  thereby  keeping 
the  reservoir  charged. 

But  suppose  something  happens  to  cause  the 
pressure  in  the  pipe  to  fall ;  the  piston  then  moves, 
closing  the  connection  between  pipe  and  reservoir, 
but  putting  the  reservoir  into  communication  with 
the  cylinder.  Compressed  air  from  the  reservoir 
then  rushes  into  the  cylinder  and  applies  the  brake. 

Thus  we  arrive  at  the  curious  fact  that  although 
the  brake  is  applied  by  the  pressure  of  air,  it  is  really 
actuated  by  a  fall  in  pressure.  The  pressure  is 
stored  up  in  the  reservoir,  and  the  fall  in  the  train 

106 


BRAKES :   HOW  THEY  WORK 

pipe  liberates  it  and  guides  it  into  the  cylinder,  there 
to  do  its  work. 

When  the  pressure  in  the  train  pipe  is  restored  the 
triple  valve  goes  back  to  its  normal  position,  putting 
the  train  pipe  into  communication  with  the  reservoir 
and  at  the  same  time  letting  out  the  air  from  the 
cylinder,  so  that  the  spring  is  able  to  assert  itself 
once  more  and  release  the  brake. 

The  driver  has,  in  his  cab,  a  gauge  which  tells 
him  the  pressure  in  the  main  reservoir  and  also  in 
the  train  pipe.  He  also  has  a  valve  by  which  he  can 
at  any  moment  lower  the  pressure  in  the  train  pipe 
and  so  put  on  the  brakes.  The  guard  has  a  valve 
too,  by  which  he  can  do  the  same  thing,  while  the 
breakage  of  a  coupling  will  do  it  automatically. 

On  electric  trains  the  compressor  is,  of  course, 
worked  by  an  electric  motor  instead  of  by  steam. 


107 


CHAPTER  VIII 

THE  CONSTRUCTION  OF  A  BRITISH 
RAILWAY 

WHEN  we  take  a  trip  on  a  railway  we  seldom 
think  much  about  how  the  line  came  to 
be  built.  It  has  probably  been  where  it 
is  as  long  as  we  can  remember,  and  we  forget  that  it 
ever  had  to  be  thought  out  and  put  there. 

Could  we  go  far  enough  back  we  should  probably 
find  that  every  railway  originated  in  the  mind  of 
some  particular  man,  probably  some  humble  in- 
dividual who  will  be  for  ever  unknown. 

It  comes  about  in  this  way.  The  people  of  some 
town  feel  the  need  for  a  better  means  of  communi- 
cation with  some  other  town  ;  a  rising  port,  perhaps, 
needs  to  attract  more  trade  ;  a  new  colliery  or  large 
factory  has  goods  which  it  wants  to  distribute  more 
expeditiously  ;  or  a  landowner  has  some  land  which, 
with  better  communication,  would  become  more 
valuable  for  residences  or  factory  sites.  These  are 
a  few  of  the  impulses  which  may  set  someone's 
mind  in  the  direction  of  promoting  a  railway. 

The  man  who  first  conceives  the  idea  talks  about 
it  to  others,  and  they  spread  the  story  until  enough 
men  have  been  gathered  together  with  sufficient 

108 


CONSTRUCTING  A  BRITISH  RAILWAY 

financial  backing  to  make  the  thing  fairly  sure  of 
success. 

There  are  generally  men  with  money  to  invest,  or 
who  can  influence  others  who  have  it,  ready  to  interest 
themselves  in  any  scheme  which  offers  a  reasonable 
prospect  of  becoming  a  paying  concern.  Thus  it  is 
not  as  difficult  to  set  going  a  project  for  building  a 
railway  as  might  at  first  sight  seem  to  be  the  case. 

The  first  essential  is  a  good  scheme  ;  a  scheme, 
that  is,  which  will  fill  a  want  or  create  a  want  on  the 
part  of  the  public.  It  is  no  good  putting  down  a 
railway  if  no  one  is  ever  wishful  to  travel  upon  it  or 
to  send  goods  by  it.  On  the  other  hand,  if  a  man 
hits  upon  the  fact,  hitherto  overlooked,  that  a  line 
from  X  to  Y  would  attract  a  lot  of  traffic,  he  has  a 
very  good  chance  of  interesting  others  who  will 
gladly  assist  in  making  the  line. 

The  promoters,  after  a  general  investigation  of  the 
matter,  usually  employ  some  eminent  firm  of  engineers 
to  investigate  it  thoroughly.  These  people,  not 
satisfied  with  the  information  to  be  culled  from  the 
Ordnance  Maps,  make  a  careful  survey  of  the  route, 
probably  of  several  alternative  routes.  One  of  these 
perhaps  will  be  the  shortest,  but  will  necessitate 
several  costly  tunnels,  cuttings,  viaducts  or  bridges. 
Another,  possibly,  will  be  longer  but  with  fewer  of 
these  difficulties.  One  may  pass  certain  villages 
where  a  little  traffic  may  be  picked  up  ;  another 
may  go  through  other  villages.  All  these  facts,  and 
many  others,  have  to  be  weighed  up  and  balanced 
against  each  other  in  order  to  decide  ultimately 
which  route  will  be  the  best  of  all. 

109 


CONSTRUCTING  A  BRITISH  RAILWAY 

As  an  example  of  the  kind  of  fact  which  may  have 
a  powerful  bearing  on  the  choice  of  route  and  yet 
may  be  quite  unnoticed  by  the  casual  observer,  we 
may  take  the  balancing  of  the  two  kinds  of  earthwork. 
A  valley,  for  instance,  may  call  for  the  construction 
of  a  long  embankment ;  the  question  then  arises, 
where  is  the  earth  to  come  from  ?  If  the  amount  of 
earth  needed  for  the  embankment  is  about  equal 
to  the  earth  which  will  be  dug  out  of  a  cutting  on 
another  part  of  the  line,  then  the  difficulty  vanishes. 
So  in  considering  the  practicability  of  a  certain 
route,  it  is  necessary  to  see  if  cuttings  and  embank- 
ments can  be  made  to  balance  each  other.  After  the 
line  is  made,  someone  comes  along  who  has  not 
carefully  gone  into  the  matter  and  indignantly  asks, 
"  Why  ever  did  they  not  take  such  and  such  a  route, 
it  would  have  been  easy  to  make  an  embankment 
across  so  and  so,"  and  probably  that  was  the  very 
thing  which  the  promoters  wanted  to  do,  but  the 
materials  for  making  that  embankment  were  not 
available. 

Let  us  suppose,  however,  that  all  these  matters 
have  been  thoroughly  thrashed  out  and  the  plans 
completed.  The  next  thing  is  to  get  authority  from 
Parliament. 

WhyTshould  that  be  necessary  ?  is  a  question  which 
may  be  asked.  A  man  can  build  a  house  if  he  wants 
to  do  so,  why  should  he  not  be  able  to  build  a  railway 
without  the  authority  of  Parliament  ? 

The  reason  is  that  the  house  builder  can  buy  his 
land  by  mutual  arrangement  with  the  owner,  whereas 
the  railway  promoters  may  come  across  a  case  where 

no 


CONSTRUCTING  A  BRITISH  RAILWAY 

they  need  a  piece  of  land  the  owner  of  which  does 
not  wish  to  part  with  it. 

Thus  one  man  could  hold  up  a  large  scheme  by 
refusing  to  sell  a  small  plot  of  ground,  and,  to  prevent 
that,  Parliament  has  to  step  in  and  give  the  pro- 
moters of  the  railway  the  power  in  such  a  case  to 
take  the  land  which  they  need,  giving  the  owner 
compensation,  of  course. 

In  the  old  days  this  led  to  many  amusing  incidents. 
Before  Parliamentary  powers  can  be  obtained  surveys 
have  to  be  made,  for  until  the  surveys  have  been 
made  the  Bill  for  presentation  to  Parliament  cannot 
be  prepared.  Consequently  it  is  necessary  for  the 
surveyors  to  go  on  to  private  land  to  make  their 
surveys  before  they  have  the  legal  right  to  do  so. 
Just  imagine,  then,  an  irate  old  farmer  who  does  not 
want  his  land  interfered  with,  finding  a  couple  of 
men  calmly  surveying  it  in  order  to  prepare  a  Bill, 
the  object  of  which  is  to  take  it  from  him.  There 
have  been  cases  where,  under  such  conditions,  a 
ferocious  bull  has  found  its  way  into  the  field  or  a 
particularly  large  dog,  to  say  nothing  of  farm  hands 
armed  with  scythes  and  other  warlike  implements. 
It  does  not  happen  often,  to-day,  because  the  modern 
farmer  realizes  that  a  new  railway  will  probably 
benefit  him  and,  at  all  events,  he  will  be  adequately 
compensated,  but  in  the  old  days  that  was  not  the 
case,  and  the  men  who  made  the  preliminary  surveys 
often  had  exciting  times. 

All  that  is  got  over  in  time  and  the  Bill  prepared. 
Like  all  Bills  it  commences  with  a  "  preamble  " 
which  sets  forth  the  reason  why  it  is  put  forward. 

in 


CONSTRUCTING  A  BRITISH  RAILWAY 

In  this  case  it  must  show  that  the  proposed  railway 
is  required  for  the  public  good.  Parliament  does 
not,  it  must  be  well  understood,  give  powers  to 
promoters  because  of  any  affection  for  them,  but 
only  because  the  scheme  they  are  proposing  to 
carry  through  is  for  the  benefit  of  the  public. 

So  the  first  thing  that  Parliament  considers  is 
whether  or  not  the  public  actually  need  the  line, 
and  whether  they  are,  therefore,  justified  in  making 
certain  individuals  do  what  they  may  not  want  to 
do,  for  the  good  of  the  community  generally. 

Bills  such  as  these  are  usually  considered  by  a 
joint  committee  of  both  the  Houses  of  Parliament, 
and  those  who  are  promoting  it,  as  well  as  those  who 
are  against  it  (for  any  interested  person  can  oppose, 
if  he  wishes  to)  can  be  represented  by  barristers 
who  can  argue  the  case  for  them. 

If  the  committee  consider  that  the  public  need  is 
not  sufficiently  great  to  justify  them  in  going  on 
with  the  Bill  they  decide  that  the  "  preamble  is  not 
proved,"  and  there  the  matter  ends.  If,  however, 
they  find  that  it  is  proved,  then  they  go  further 
into  the  matter,  clause  by  clause,  until  every  detail 
has  been  thoroughly  thrashed  out  and  settled. 

After  all  the  formalities  have  been  gone  through 
and  probably  a  great  many  changes  made  in  order 
to  reconcile  many  interests,  the  Bill  is  passed  and 
becomes  an  Act  of  Parliament.  Many  of  the  curious 
and  unaccountable  things  which  railways  do,  by 
the  way,  is  the  result  of  compromises  which  are 
made  as  the  Bill  goes  through  Parliament,  in  order 
to  harmonize  conflicting  interests. 

112 


£  T 

2  1  . 

?  *  s 

o  §  g> 

u  S  ° 

aj  u 

^  -s  s 

S5  &  a 


CONSTRUCTING  A  BRITISH  RAILWAY^ 

The  next  step  is  to  make  a  contract  with  someone 
for  the  construction  of  the  line.  A  vast  number  of 
drawings  are  first  produced  by  the  engineers,  giving 
all  manner  of  details.  In  fact,  the  line  is  first  con- 
structed in  the  minds  of  the  draughtsmen  in  the 
engineer's  office,  to  an  extent  which  would  surprise 
many  non-technical  people.  The  smallest  details 
are  carefully  thought  out  and  put  down  on  paper. 

From  these  drawings  a  schedule  of  quantities  is 
prepared,  by  which  is  meant  lists  of  the  materials 
to  be  supplied  and  work  to  be  done.  These  lists, 
too,  are  wonderfully  complete,  considering  that  so 
far  the  thing  only  exists  in  imagination. 

Copies  of  the  schedules  are  sent  out  to  the  people 
who  are  invited  to  tender  for  the  work,  while  the 
drawings  are  placed  in  some  convenient  room,  so 
that  those  who  are  going  to  tender  can  come  and 
study  them. 

Then  each  tenderer  puts  down  his  prices  against 
the  items  in  the  lists  (there  are  possibly  thousands 
of  items)  works  them  all  out,  adds  them  up,  makes 
allowances  for  any  special  risks  or  liabilities  which 
occur  to  him  and  finally  arrives  at  a  total.  This  he 
fills  in  upon  the  tender  form  prepared  for  the  purpose 
and  sends  it  in. 

On  a  certain  day  the  directors  of  the  railway 
company  (for  such  the  promoters  have  now  become) 
sit  in  state  for  the  purpose  of  receiving  these  tenders. 
They  all  come  in  sealed  envelopes  and  are  opened 
at  the  meeting.  A  list  of  them  is  usually  made, 
after  which  they  are  referred  to  the  engineer  and  other 
officials  for  them  to  go  through  and  report  upon. 
H  113 


CONSTRUCTING  A  BRITISH  RAILWAY 

At  a  subsequent  meeting  one  is  accepted,  not  always 
the  lowest,  but  the  one  that  the  directors  consider 
most  beneficial  after  taking  everything  into  account. 

Meanwhile,  of  course,  negotiations  have  been  going 
on  for  the  purchase  of  the  necessary  land.  In  most 
cases  the  company's  land  agents  will  be  able  to 
arrange  amicably  with  the  owners,  but  in  a  few, 
possibly,  the  price  will  have  to  be  settled  by  arbitra- 
tion. 

As  soon  as  it  can  be  arranged  the  land  passes, 
piece  by  piece,  if  necessary,  into  the  hands  of  the 
contractors,  who  then  commence  active  operations. 

The  work  is  attacked  at  many  convenient  points, 
a  bridge  here,  a  tunnel  there,  a  cutting  somewrhere 
else,  the  trains  with  spoil  from  the  cuttings  running 
to  the  places  where  embankments  are  required. 
Where  an  embankment  has  to  be  interrupted  to 
allow  a  road  to  pass,  and  the  line,  as  so  often  is  the 
case,  has  to  be  carried  upon  a  brick  arch,  the  brick- 
work is  done  first,  the  bricks  being  carted  by  road, 
so  that  the  arch  stands  for  a  time  isolated  amid  the 
surrounding  country,  often  looking  very  strange, 
like  a  monumental  arch  that  has  lost  its  way.  Gradu- 
ally, however,  the  earthen  embankment  is  creeping 
along.  The  little  tipping  trucks  with  earth  come 
along  temporary  lines  laid  on  that  part  of  the  bank 
which  is  finished,  and  each  tips  up  at  the  end  of  its 
run,  dropping  its  contents  down  the  steep  side  of, 
or  rather  end  of,  the  growing  heap.  Thus  the  earth- 
work goes  on  until  it  reaches  the  isolated  arch  and 
permits  the  line  to  be  carried  on  over  it. 

Where  wider  and  more  important  roads  call  for 

114 


CONSTRUCTING  A  BRITISH  RAILWAY 

a  steel  bridge,  the  brick  or  stone  abutments  which 
support  its  ends  are  built  up  and  the  embankment 
brought  up  to  them,  the  steel  girders  being  either 
hoisted  up  from  the  road  below  or  else  carried  by 
rail  on  the  line  above  at  a  later  stage. 

Tunnelling  is  a  problem  which  has  to  be  faced  in 
the  construction  of  most  lines,  but  that  will  be  dealt 
with  fully  in  another  chapter. 

Where  large  excavations  have  to  be  made,  such 
as  deep  cuttings,  mechanical  aids  are  employed  in 
addition  to  the  pick  and  shovel  of  the  navvy.  These 
machines  are  called  steam  navvies,  or  sometimes 
mechanical  shovels. 

Speaking  of  names,  it  is  rather  interesting  to  trace 
the  origin  of  the  word  navvy.  It  dates  back  a 
hundred  years  or  so  to  the  time  when  canals  were 
being  constructed  all  about  the  country,  just  before 
the  era  of  railways.  Attracted  by  the  better  wages 
to  be  earned,  many  men  who  till  then  had  been 
agricultural  labourers  drifted  away  from  the  country- 
side to  the  canal  works,  where  they  were  employed 
mainly  in  digging  out  the  earth  to  form  the  water- 
ways. Passing  from  place  to  place,  wherever  the 
work  might  be  going  on  at  the  moment,  they  ac- 
quired considerable  skill  in  their  work,  so  that 
eventually  they  became  a  semi-skilled  class,  and 
whenever  a  new  canal  was  started  the  contractors 
naturally  looked  about  to  find  as  many  men  as 
possible  of  this  class,  for  it  is  quite  a  mistake  to 
think  that  any  able-bodied  man  can  do  navvy's 
work,  without  experience. 

It  is  probable  that  the  outdoor  nature  of  the  life 


CONSTRUCTING  A  BRITISH  RAILWAY 

attracted  many  men,  and  the  frequent  moving  from 
one  job  to  another  satisfied  the  roving  instinct  which 
afflicts  a  good  many  Britishers. 

Anyway,  this  class  came  into  existence  and  the 
work  upon  which  they  specialized,  which  had, 
indeed,  called  them  as  a  class  into  existence,  was  the 
construction  of  "  navigation  canals,"  whence  they 
came  to  be  termed  navigators,  which  in  time  was 
corrupted  into  "  navvies." 

But  to  return  to  the  steam  navvy.  This  is  a 
powerful  machine  mounted  upon  wheels  so  that  it 
can  be  moved  upon  rails  which  are  laid  down  specially 
for  it.  It  contains  a  steam  engine,  complete  with  its 
boiler,  also  a  long,  powerful  arm  which  it  can  raise 
and  lower  at  will.  At  the  extremity  of  the  arm  is 
what  might  be  called  a  gigantic  hand  with  its  palm 
upwards,  the  finger  nails,  to  complete  the  simile, 
being  pointed  and  strong. 

Let  us  picture  it  at  work  on  the  side  of  a  hill  into 
which  it  is  digging  its  way  in  order  to  cut  out  one  of 
those  huge  furrows  which  we  call  a  railway  cutting. 

It  stands  upon  a  small  piece  of  level  ground  which 
has  been  prepared  as  its  starting-point,  and  from 
that  it  advances  towards  the  side  of  the  hill.  Then 
it  lowers  its  arm  to  the  ground  level,  immediately 
raising  it  again  in  a  powerful  sweep,  scooping  away, 
as  it  does  so,  a  huge  handful  of  earth  from  the  hill- 
side. The  lifted  earth  is  then  dropped  out  through 
a  trap  door  which  forms  the  palm  of  the  "  hand  " 
into  a  waiting  truck,  and  the  hand  descends  once 
more  to  pick  up  another  handful. 

One  of  these  machines  can  pick  up  as  much  as 
116 


CONSTRUCTING  A  BRITISH  RAILWAY 

half  a  ton  of  earth  at  one  movement,  so  it  is  easy  to 
see  that  under  favourable  conditions  it  can  displace 
quite  a  large  number  of  its  human  namesakes. 

Speaking  generally,  however,  there  is  not  a  great 
amount  of  machinery  used  in  the  construction  of  a 
railway.  There  are  lots  of  trucks  and  wagons  of 
various  sorts  and  small  locomotives  to  haul  them 
about,  also  a  few  cranes  mounted  upon  railway 
wheels  so  that  they  can  be  moved  about  for  lifting 
heavy  stones  and  the  like,  also,  in  special  places 
steam  navvies,  but  on  the  whole  the  construction  of 
a  railway  is  largely  the  work  of  the  human  machine. 
The  reason  for  this  is  that  the  work  is  so  varied 
and  spread  out  over  so  large  an  area  that  nothing 
can  compare  with  that  most  mobile  and  adaptable 
of  all  machines,  the  human  body. 

When  all  the  earthwork  has  been  done  the  line  is 
by  no  means  finished.  The  temporary  tracks  laid 
down  by  the  contractors  for  their  own  convenience 
are  not  suited  for  the  regular  traffic.  For  one  thing, 
they  rest  merely  upon  earth,  which  under  the  pressure 
of  the  ordinary  loads  of  a  railway  would  give  way. 
The  small,  light  engines  and  the  little  trucks  of  the 
contractor  can  safely  pass  over  tracks  which  would 
be  hopelessly  weak  for  heavy  goods  and  passenger 
engines  with  their  trains. 

The  level  to  which  the  earthwork,  the  founda- 
tions of  the  line,  are  raised  is  called  "  formation  level." 
Upon  the  top  of  that  comes  the  ballast  to  a  depth  of 
about  18  ins. 

This  consists  of  stones  of  varying  sizes.  Such 
stuff  as  shingle  from  the  seashore  is  used  in  some 

117 


CONSTRUCTING  A  BRITISH  RAILWAY 

places,  but  better  still  is  stone  from  a  quarry,  because 
the  rough  surfaces  and  sharp  corners  of  the  latter 
cause  it  to  bind  together  better  into  a  mass  which 
is  solid  and  strong,  yet  has  interstices  through  which 
water  can  make  its  way  downwards. 

The  purpose  of  the  ballast  is  to  distribute  the 
weight  so  that  each  sleeper  really  may  rest  upon  an 
area  of  earth  much  larger  than  its  own  area,  also  to 
afford  drainage  so  that  the  timber  sleepers,  being 
kept  dry,  may  last  longer,  and  finally  to  keep  the 
sleepers  in  place  so  that  they  will  not  slide  sideways. 

Large  lumps  of  stone  are  placed  at  the  bottom 
of  the  ballast,  in  contact  with  the  earth,  the  successive 
layers  being  made  of  smaller  and  smaller  material 
up  to  the  top,  where  the  pieces  are  quite  small.  In 
this  top  layer  the  sleepers  are  buried. 

The  chairs,  which  are  made  of  cast  iron,  are 
fastened  to  the  sleepers  with  iron  spikes  and  in 
some  cases  oak  pegs.  The  rails  are  laid  in  the  chairs 
and  then  fastened  in  by  means  of  blocks  of  oak 
driven  in  tightly.  These  blocks  are  termed  keys, 
and  so  important  is  their  function  that  the  "  plate- 
layers "  who  look  after  the  line  spend  quite  a  con- 
siderable part  of  their  time  watching  them,  and  by 
judicious  blows  of  a  special  kind  of  hammer  which 
they  carry  keeping  them  tight. 

It  is  not  generally  realized  that  the  chairs  are  so 
shaped  that  the  rails  are  not  upright,  but  cant  slightly 
inwards.  This  is  to  make  them  fit  approximately 
the  slope  of  the  wheels. 

The  wheels  are  not  cylindrical,  but  slightly  conical, 
so  that  they  have  a  natural  tendency  to  keep  on 

118 


CONSTRUCTING  A  BRITISH  RAILWAY 

the  rails  apart  from  the  action  of  the  flange  or  rim 
which  they  all  have. 

Where  a  branch  or  a  cross-over  occurs,  points  or 
switches  and  crossings  are  required.  At  each  point 
one  rail  called  the  "  stock  rail  "  runs  right  through, 
while  another  rail,  the  end  of  which  is  tapered  off 
to  a  point,  is  pivoted  near  to  it,  so  that  it  can  be 
made  to  lie  close  alongside,  or  be  removed  to  a  distance 
of  about  4  ins.  In  the  first  position  this  "  tongue," 
as  it  is  termed,  guides  the  flange  of  the  wheel  to  one 
side  or  the  other,  while  in  the  second  position  it 
leaves  a  wide  enough  gap  for  the  flange  to  pass 
through. 

The  purpose  of  a  crossing  is  to  form  a  gap  in  the 
rails  through  which  the  flange  of  the  wheels  can  pass 
as  a  train  crosses  over. 

Points  and  crossings  are  places  where  there  is  a 
remote  possibility  of  a  vehicle  being  thrown  off  the 
line,  so  they  are  always  protected  by  "  guard  rails,'? 
extra  pieces  of  rail  upon  which  the  train  does  not 
run,  but  which,  because  of  their  situation,  tend  to 
prevent  it  leaving  the  other  rail.  The  way  in  which 
these  guard  rails  act  will  be  made  quite  clear  by  a 
glance  at  the  diagram  on  page  123. 

Most  branches  are  on  a  level,  so  that  one  of  the 
branch  lines  has  to  cross  the  opposite  main  line. 
This  is  done  by  means  of  crossings  just  like  those 
used  with  points.  In  busy-  lines,  however,  such 
arrangements  are  very  inconvenient. 

Take  as  an  example  the  case  of  a  branch  which 
curves  off  in  a  "  down  "  direction,  and  to  the  right. 
The  "  down  "  branch  line  then  crosses  the  "  up  " 

119 


CONSTRUCTING  A  BRITISH  RAILWAY 

main  line,  and  the  passage  of  a  main  line  train  may 
have  to  be  held  up  for  a  considerable  time  in  order 
to  allow  a  branch  train  to  cross,  or  vice  versa.  There- 
fore, on  busy  lines,  crossings  on  the  level  are  often 
avoided  by  means  of  "  fly-over  "  junctions.  If  the 
illustration  just  referred  to  were  of  the  "  fly-over  " 
variety  the  "  up  "  branch  would  simply  curve  round 
in  the  ordinary  way,  for  it  crosses  nothing,  but  the 
down  branch  would  first  curve  to  the  left  and  then 
swing  round  to  the  right,  passing  either  under  or 
over  the  main  line.  The  mutual  interference  of  the 
two  lines  is  then  reduced  to  the  minimum. 

The  lines  laid  by  the  contractors,  as  we  have  seen, 
are  quite  temporary,  being  taken  up  when  they  have 
served  their  purpose,  to  give  way  to  lines  of  a  "  per- 
manent "  nature.  Hence  the  rails,  ballast  and  all 
connected  with  them  are  spoken  of  in  railway 
language  as  the  "  permanent  way." 

When  the  railway  is  completed  it  is  divided  up 
into  areas,  each  of  which  is  put  under  the  care  of  a 
"  permanent  way  inspector,"  who,  under  the  general 
direction  of  the  District  Engineer,  is  responsible  for 
the  "  permanent  way  "  being  kept  in  perfect  order. 
He  has  under  him  a  number  of  gangs  of  plate- 
layers, each  headed  by  a  "  ganger."  Each  ganger 
has  a  "  length  "  of  line  to  look  after  ;  it  may  be 
several  miles  or  it  may  be  less,  according  to  the 
number  of  lines  and  amount  of  traffic.  On  some 
railways  the  lengths  are  marked  off  from  each 
other  by  posts  with  the  names  of  the  respective 
gangers  painted  on  opposite  sides.  Every  ganger  is 
supposed  to  walk  over  his  "  length  "  once  on  Sunday 

120 


CONSTRUCTING  A  BRITISH  RAILWAY 

and  twice  every  weekday.  His  keen,  practised  eye 
soon  catches  sight  of  anything  in  the  least  degree 
wrong  ;  if  it  be  within  his  scope  he  puts  it  right, 
either  himself  or  by  his  gang  ;  if  not  he  reports  it. 

Thus  we  see  how  the  line  is  made  and  also  the 
scrupulous  care  which  is  subsequently  exercised  to 
keep  it  in  the  most  perfect  order.  It  is  to  this 
methodical  care  that  we  owe  in  a  large  degree  that 
almost  perfect  safety  which  we  enjoy  when  we  travel 
by  train. 


121 


CHAPTER  IX 
HOW  RAILS  ARE  MADE 

THE  railway  is  much  older  than  the  locomotive. 
Many  years  before  the  birth  of  Trevithick 
or  Stephenson  there  were  railways  along 
which  trucks  were  drawn  by  horses.  Like  most 
other  things  these  were  the  result  of  slow  growth 
or  evolution,  rather  than  the  sudden  invention  of 
one  man. 

Starting  from  the  rough  path  made  by  a  succession 
of  carts  passing  over  the  same  route  came  the  made- 
up  road  where  stones  or  other  hard  material  was 
placed  in  order  to  produce  a  harder  and  smoother 
surface. 

From  this  it  was  but  a  step  to  lay  down  timbers 
for  the  wheels  of  the  carts  to  run  on.  These  in  turn 
gave  place  to  cast-iron  plates,  and  it  is  a  curious 
instance  of  the  survival  of  words  that  the  men  who 
to-day  lay  and  look  after  the  rails  upon  the  modern 
railway  are  not  rail -layers,  but  plate-layers. 

In  the  early  stages  the  plates  had  raised  edges  for 
the  purpose  of  keeping  the  wheels  from  running  off. 
This  had  the  disadvantage  that  plates  so  shaped 
formed  gutters  in  which  stones  collected,  and  that 
led  to  the  next  stage  in  which  the  plates  were  quite  flat, 
while  a  raised  edge  or  flange  was  put  upon  the  wheels. 

122 


HOW  RAILS  ARE  MADE 

The  trouble  with  the  cast-iron  plates  was  that  as 
the  size  of  the  wagons  increased  they  became  more 
and  more  liable  to  break.  Hence  the  introduction 
of  rails  of  wrought  iron,  a  much  tougher  material 
than  cast  iron. 

Wrought  iron  has  in  its  turn  been  displaced  by  the 
"  mild  steel  "  of  the  present  day. 


;Fig.  8. — A  PAIR  OF  POINTS  AND  A  CROSSING. 

(1)  These  are  the  stockrails.     They  are  fixed,  like  ordinary 
rails.     Notice  that  every  train  has  one  fixed  rail  to  run  upon. 

(2)  The  tongues  of  the  points.     It  is  by  moving  these  that 
the  points  are  set  to  guide  tha  train  as  required. 

(3)  Guard  rails.     Notice  that  for  a  train  to  leave  the  rails 
the  flanges  of  the  wheels  must  jump  over  the  guard  rails. 

What,  then,  is  this  mild  steel,  and  why  is  it  called 
"  mild  "  ? 

Like  all  forms  of  steel  it  is  an  alloy  of  iron  and 
carbon.  Pure  iron  is  almost  useless,  for  the  reason 
that  it  is  too  soft.  For  practical  use  it  needs  the 
hardening  effect  of  carbon.  Pig  iron,  which  is  the 
raw  material  from  which  all  other  forms  of  iron  are 
made,  contains  at  least  2  per  cent  of  carbon.  Wrought 
iron  contains  a  small  fraction  of  one  per  cent,  and 
between  the  two  come  all  the  different  varieties  of 

123 


HOW  RAILS  ARE  MADE 

steel.  Steel  which  contains  less  than  one-half  of 
one  per  cent  is  called  "  mild  "  steel,  the  rest  being 
grouped  together  as  hard  steel. 

Iron  ore  is  one  of  the  commonest  of  substances. 
It  is  to  be  found  almost  everywhere,  but  all  of  it 
cannot  be  used,  since  some  of  it  contains  so  little  iron 
that  to  work  it  would  be  too  costly,  while  in  other 
cases  it  is  so  contaminated  with  impurities  as  to  be 
useless. 

It  is  generally  obtained  from  quarries  open  to  the 
air  rather  than  from  underground  mines,  and  it  is 
broken  down  by  blasting  or  other  quarrying  methods, 
just  like  stones  for  road  metal.  Then  it  is  taken  to 
the  iron  works  to  be  smelted. 

At  the  iron  works  there  are  huge  structures  called 
"  blast  furnaces,"  great  tall  chimney -like  affairs 
built  of  steel  and  brickwork  and  lined  with  fire- 
brick. In  the  bottom  of  the  furnace  a  fire  is  made, 
and  this  is  urged  to  an  intense  heat  by  a  "  blast  "  of 
air  which  is  driven  in  upon  it  from  nozzles  placed 
all  round  the  zone  where  the  fire  is. 

The  blast  is  produced  by  huge  air-pumps  driven  by 
a  powerful  steam  or  gas  engine. 

Roughly  speaking,  then,  we  may  describe  the 
blast  furnace  as  a  huge  tube,  perhaps  70  ft.  long, 
set  up  on  end,  the  bottom  end  being  closed  and  the 
top  open,  with  the  fire  lying  in  the  bottom  end. 
There  are  no  fire-bars  or  grate  of  any  description, 
the  fire  simply  lying  on  the  solid  bottom,  the  oxygen 
necessary  for  its  burning  being  blown  in  from  the 
nozzles. 

Near  the  top  end  is  a  stage  reached  by  a  hoist, 

124 


HOW  RAILS  ARE  MADE 

and  from  this  point  the  ore  is  tipped  so  that  it  falls 
down  and  mingles  with  the  fire  below.  Ore,  fuel  and 
limestone  are  continually  being  thrown  in,  in  the 
proper  proportions,  and  the  blowing  engine  is  blowing 
air  into  the  mass  every  hour  of  the  day  and  night. 

Now  it  must  be  understood  that  iron  ore  does  not 
appear  at  all  like  iron.  It  is  usually  a  reddish- 
looking  rock.  It  is  chiefly  oxide  of  iron,  but  is  mixed 
up  with  earthy  matters  of  various  sorts.  An  oxide 
of  iron,  of  course,  is  a  combination  of  iron  and 
oxygen,  and  the  purpose  of  the  blast  furnace  is  to 
dissolve  that  combination  and  to  free  the  iron  from 
its  partner. 

Heat  alone  will  not  do  this.  It  will  loosen  the 
bonds  between  iron  and  oxygen,  but  it  will  not 
separate  them.  In  order  to  separate  them  it  is 
necessary  to  place  the  ore  in  the  neighbourhood  of 
some  other  matter  for  which  the  oxygen  has  a  greater 
"  affinity  "  than  it  has  for  iron.  Fortunately  carbon 
fulfils  this  condition,  and  so  when  heated  sufficiently 
the  oxygen  leaves  the  iron  and  joins  the  carbon, 
of  which  there  is  a  plentiful  supply  in  the  fuel. 

It  is  for  this  reason  that  ore  and  fuel  are  mixed 
up  together.  The  fuel  serves  a  double  purpose  ;  it 
supplies  the  heat  and  it  also  entices  the  oxygen 
away  from  the  iron,  which  latter  purpose  it  could 
not  serve  unless  it  were  close  to  it. 

The  liquid  iron  thus  formed  collects  in  the  bottom 
of  the  furnace,  the  fire  actually  floating  upon  the 
top  of  a  pond  of  molten  iron.  Periodically  the 
furnace  is  tapped  ;  a  small  hole  normally  plugged 
with  clay  is  unstopped  and  out  runs  the  metal. 

125 


HOW  RAILS  ARE  MADE 

Periodically,  too,  a  hole  higher  up  is  opened  and 
from  it  is  drawn  a  liquid  which  is  termed  "  slag." 
It  consists  mainly  of  the  earthy  impurities  out  of 
the  ore.  The  slag,  when  cool,  sets  into  a  hard  rock- 
like  substance  which  is  used  largely  for  making 
roads. 

Before  we  follow  the  history  of  the  molten  iron 
to  the  next  stage  we  should  take  a  final  look  at  the 
blast  furnace. 

In  the  old  days  the  top  was  left  permanently 
open  and  flames  belched  forth,  lighting  up  the  sky 
by  night  in  a  very  picturesque  manner.  Its  beauty, 
however,  did  not  atone  for  the  wastefulness  of  this 
arrangement.  Those  flames  were,  in  fact,  valuable 
gases  burning  uselessly,  so  now  they  are  led  away 
and  form  a  valuable  asset  to  the  works. 

In  order  to  do  this  the  top  of  the  furnace  is  partially 
closed  by  a  sort  of  basin  with  a  large  hole  in  the 
centre.  Into  this  hole  there  fits  a  cone-shaped  plug, 
the  point  of  the  cone  being  upwards  and  the  plug 
being  held  up  by  means  of  a  chain.  The  ore,  fuel 
and  limestone  are  tipped  into  the  basin  until  it  is 
full,  and  then  the  plug  is  lowered  for  a  moment  to 
allow  them  to  fall  into  the  furnace.  The  plug  is 
immediately  raised  again,  so  that  except  for  those 
brief  intervals  when  the  furnace  is  actually  being 
charged  the  top  of  it  is  closed.  The  gases  which 
would  otherwise  ignite  and  form  flames  at  the  top 
(which,  indeed,  they  do  when  the  charge  is  being 
dropped  in)  are  led  away  through  a  huge  pipe. 
What,  then,  is  done  with  them  ? 

Often  they  are  burnt  in  the  furnaces  of  boilers  for 

126 


HOW  RAILS  ARE  MADE 

raising  steam  for  the  steam  engines.  They  are  also 
used  to  heat  the  blast  for  the  furnaces.  In  some 
cases  they  are  used  to  drive  enormous  gas  engines. 
In  some  works  they  cannot  profitably  employ  the 
huge  quantities  of  this  "  blast  furnace  gas  "  which  is 
available,  and  subsidiary  industries  have  been,  or 
may  well  be,  added  to  the  works  in  order  not  to 
waste  them. 

Let  us  now  return  to  the  iron.  It  flows  from  the 
furnace  along  a  spout  on  to  the  pig  bed,  a  bed  of 
sand  in  which  grooves  have  been  made.  These 
grooves  are  filled  by  the  iron  which,  when  it  has  set, 
becomes  what  is  known  as  pig  iron.  This  can  be  re- 
melted  in  a  cupola  and  used  to  make  castings  as 
described  elsewhere,  or  it  can  be  taken  to  the  steel- 
works for  making  steel.  At  this  stage,  let  it  be 
remembered,  the  iron  contains  about  two  per  cent 
or  more  of  carbon,  besides  other  impurities,  such  as 
sulphur,  phosphorous,  silicon  and  so  on.  It  is  fairly 
hard,  but  compared  with  the  other  forms  of  iron 
and  steel  it  is  brittle.  It  is  the  material  of  which  the 
first  metal  "  plates  "  were  made  for  the  primitive 
horse  railways. 

These  "  cast-iron  "  plates  were,  it  will  be  remem- 
bered, succeeded  by  "  rails  "  of  "  wrought  iron." 
This  material  is  tough  ;  unlike  cast  iron  it  can  be 
bent ;  it  cannot  be  melted,  but  it  can  be  softened 
by  heating  and  then  shaped  by  hammering  or  by 
passing  between  grooved  rollers.  It  is  less  prone 
to  rust  than  is  mild  steel  and  it  can  be  welded,  but 
in  almost  every  other  respect  the  newer  "  mild 
steel  "  is  superior. 

127 


HOW  RAILS  ARE  MADE 

In  order  to  change  pig  iron  into  wrought  iron  the 
pig  iron  is  melted  and  kept  liquid  in  a  special  kind 
of  furnace,  called  a  "  puddling  furnace."  This  is 
not  a  large  structure  and  may  be  described  as  a 
shallow  bath  of  fire-brick  with  a  furnace  attached, 
things  being  so  arranged  that  the  flames  from 
the  fire  play  upon  the  metal  as  it  lies  in  the 
bath. 

A  workman,  called  a  "  puddler,"  then  stirs  the 
metal  about  with  a  rod,  thereby  exposing  it  to  the 
action  of  oxygen  and  causing  the  carbon  to  be 
gradually  burnt  out  of  it.  Now  the  reduction  of 
the  carbon  raises  the  melting  point  so  that  as  the 
metal  loses  carbon  it  becomes  less  fluid,  and  finally 
adheres  in  the  form  of  a  lump  to  the  end  of  the 
stirrer.  The  puddler  thus  forms  lump  after  lump 
of  de-carbonized  metal,  each  lump  as  formed  being 
drawn  out  of  the  furnace.  The  lumps  are  at  the 
next  stage  heated  again,  hammered  together  into  a 
larger  lump,  which  again  is  passed  between  grooved 
rollers  and  thereby  formed  into  bars  of  whatever 
shape  may  be  desired.  The  oxides  which  form  on 
the  surface  of  the  lumps,  and  certain  other  im- 
purities, cause  these  bars  when  rolled  to  be  of  a 
fibrous  nature,  the  fibres  running  lengthwise  of  the 
bar.  Thus  wrought  iron  has  a  texture  almost  like 
that  of  wood  and,  again  like  wood,  it  has  less  strength 
across  the  grain  than  with  it.  Still,  it  was  and  is 
still  to  a  less  degree,  a  very  useful  material  to  which 
the  railway  owes  a  great  debt.  Of  it  all  rails  were 
made  for  many  years,  certain  things,  such  as  rivets, 
are  made  still,  and  it  is  even  now  preferred  for  bridges 

128 


SAWING  COLD  STEEL. 

The  remarkable  machine  illustrated  here  is  described  in  the  text.  The  article 
to  be  cut  is  fixed  upon  a  moving  table  and  moved  against  the  saw.  The  saw  is  just 
a  disc  of  steel  plate  and  it  cuts  through  material  even  harder  ihin  itself  because  of  its 
high  speed  of  rotation.  (Photographed  at  the  L.  &  N.W.R.  Works,  at  Crewe). 


HOW  RAILS  ARE  MADE 

by  some  engineers  on  account  of  its  superior  rust- 
resisting  powers. 

Now  we  come  to  the  steel  of  which  rails  are 
made  to-day  and  are  likely  to  be  made  for  many 
years  to  come,  since  no  rival  material  is  yet  in 
sight. 

There  are  two  methods  of  making  this  steel,  one 
called  the  "  Bessemer  "  process,  after  its  inventor, 
Sir  Henry  Bessemer,  and  the  other  the  "  open- 
hearth  "  process. 

The  Bessemer  process  is  carried  on  in  a  curious 
kind  of  "  fuel-less  "  furnace  called  a  "  converter." 
It  is  a  huge  steel  pear-shaped  vessel,  lined  with  non- 
fusible  sand  and  mounted,  like  the  kettles  which 
sometimes  grace  the  tea-table,  upon  "  trunnions," 
so  that  it  can  easily  be  turned  over  on  to  its 
side. 

When  in  this  position  molten  pig  iron  is  brought 
along  and  poured  into  it.  One  may  be  inclined  to 
ask,  why,  if  it  be  on  its  side,  does  not  the  iron  run 
out  again  ?  and  the  answer  is  that  its  comparatively 
narrow  neck  enables  it  to  hold  a  certain  amount  of 
liquid  even  when  on  its  side. 

Next  the  blast  is  turned  on  and  air  begins  to  blow 
violently  through  holes  in  the  bottom  of  the  con- 
verter, which  is  then  turned  into  an  upright  position, 
so  that  the  air  blows  up  through  the  metal.  This 
causes  the  carbon  to  be  burnt  out  and,  in  fact,  renders 
it  practically  free  from  carbon,  too  free  for  practical 
purposes.  There  is,  therefore,  added,  after  the  blow- 
ing has  ceased,  a  quantity  of  a  special  sort  of  pig 
iron  containing  a  known  amount  of  carbon.  Thus, 
i  129 


HOW  RAILS  ARE  MADE 

to  put  it  simply,  all  the  carbon  is  first  burnt  out  and 
then  the  correct  quantity  of  it  is  put  back. 

The  strange  feature  about  this  which  gave  rise 
to  the  term  "  fuel-less  furnace,"  used  just  now,  is 
that  although  no  visible  fuel  is  used  the  metal  comes 
out  of  the  converter  hotter  than  it  goes  in,  the 
carbon  actually  contained  in  the  pig  iron  forming 
the  fuel  which  brings  about  this  result. 

This  method  is  quick,  but  for  that  very  reason 
difficult  to  control ;  hence  Bessemer  steel  is  sometimes 
a  trifle  suspect  as  regards  its  quality.  The  rival 
process  is  much  slower,  samples  can  be  taken  from 
time  to  time  and  subjected  to  tests  ;  hence  it  is  on 
the  whole  more  reliable. 

Imagine  an  enormous  bath  holding  perhaps  50 
tons  of  molten  iron.  The  bath  itself  and  the  low 
roof  over  are  formed  of  fire-brick  with  linings  of 
infusible  sand.  Over  the  metal  there  play  huge 
flames  coming  apparently  from  nowhere.  The 
mystery  is  explained  by  the  fact  that  the  furnace 
is  fired  by  gas  and  not  by  solid  fuel.  The  coal  or 
coke  is  changed  into  gas  in  a  plant  called  a  "  gas- 
producer  "  situated  near  by,  and  the  gas  is  led 
through  great  flues  of  brickwork  into  the  furnace. 
It  must  not  be  supposed  that  this  is  coal  gas  such 
as  we  burn  in  our  houses  ;  it  is  "  producer  "  gas, 
practically  the  whole  of  the  fuel  being  changed  into 
a  gaseous  form.  It  is  not  clean  enough  for  domestic 
use,  but  on  the  other  hand  coal  gas  would  be  too 
expensive  for  making  steel. 

Arriving  in  the  furnace  through  the  flues  at  one 
end  the  gas  mingles  with  air  from  another  flue  and 

130 


HOW  RAILS  ARE  MADE 

thereupon  bursts  into  flame,  the  low  roof  of  the 
furnace  being  so  shaped  as  to  throw  the  heat  down 
upon  the  metal  as  much  as  possible. 

The  waste  gases,  the  "  burnt  "  gases  we  mi;;ht 
call  them,  pass  out  through  flues  at  the  opposite 
end  of  the  furnace,  and  in  this  connection  we  see 
a  beautifully  simple  example  of  how  to  save 
waste. 

These  furnaces  are  called  "  regenerative  "  because 
a  lot  of  the  heat  of  the  waste  gases  is  caught  and 
brought  back  again  into  the  furnace.  The  outgoing 
gases  traverse  a  series  of  flues  which  lead  them 
through  chambers  filled  with  loosely  stacked  bricks. 
The  gases,  passing  between  and  among  these  bricks, 
give  up  a  great  deal  of  their  heat,  making  the  bricks 
hot  instead.  When  this  has  been  going  on  for  a 
time  and  the  bricks  are  very  hot,  the  course  of  the 
gases  is  reversed  and  the  fresh  gas  and  the  air  to 
burn  with  it  enter  through  the  hot  chambers.  Doing 
so,  they  pick  up  heat  from  the  bricks  and  bring  it 
back  into  the  furnace,  in  their  turn  heating  up  the 
bricks  on  the  other  side.  Thus  the  new  gas  and  air 
are  continually  restoring  to  the  furnace  heat  which 
the  waste  gases  have  just  taken  out.  The  reversal 
of  the  course  of  the  air  and  gas  goes  on  at  intervals 
all  the  time  the  furnace  is  at  work. 

If  you  open  the  door  of  one  of  these  furnaces  and 
attempt  to  look  in  with  naked  eyes  you  can  see 
nothing.  If,  however,  you  put  on  dark  spectacles  or 
look  through  a  sheet  of  dark  glass  you  see  a  most 
beautiful  spectacle,  a  lake  of  liquid  gold.  As  ore  or 
other  materials  are  thrown  in  the  liquid  splashes 


HOW  RAILS  ARE  MADE 

about  with  effects  far  more  beautiful  than  the  finest 
fireworks. 

But  how  does  all  this  change  the  iron  into  steel  ? 

It  is  done  by  the  addition  of  suitable  quantities 
of  a  kind  of  iron  ore  called  "  hematite,"  which 
contains  a  lot  of  oxygen.  The  oxygen  from  this  ore 
combines  with  the  carbon  in  the  rest  of  the  iron  and 
both  leave  the  furnace  in  the  form  of  carbonic  acid 
gas.  By  the  proper  manipulation,  therefore,  of  the 
furnace,  and  the  addition  of  the  right  quantities  of 
hematite,  the  desired  percentage  of  carbon  in  the 
whole  mass  of  metal  can  be  attained.  And  the 
process  is  sufficiently  slow  to  permit  of  samples 
being  taken  from  time  to  time  to  ensure  that  all  is 
as  it  should  be. 

Each  of  these  processes  is  again  divided  into  two, 
described  as  "  acid  "  and  "  basic  "  respectively.  It 
is  only  necessary  to  mention  these  in  case  the  reader 
has  seen  them  referred  to  and  would  like  to  know  their 
meaning.  The  difference  is  in  the  material  with 
which  the  furnace  or  converter,  as  the  case  may  be, 
is  lined.  Each  has  the  power  of  absorbing  and  so 
removing  from  the  metal  some  impurity.  For 
instance,  some  forms  of  pig  iron  contain  a  high 
percentage  of  phosphorous,  an  element  which  is 
fatal  to  good  steel.  By  giving  a  "  basic  "  lining  to 
the  furnace  or  converter  this  is  extracted  from  the 
metal,  and  thus  ores  which  would  otherwise  be 
useless  can  be  turned  into  good  steel. 

The  steel  industry  of  Germany  in  particular 
benefited  from  the  invention  of  the  basic  process, 
for  there  are  vast  supplies  of  ore  in  Lorraine  and 

132 


HOW  RAILS  ARE  MADE 

Luxemburg  which  were  till  then  useless.  For  this 
process  to  work  well  the  percentage  of  phosphorous 
in  the  ore  needs  to  be  fairly  high  to  commence  with, 
and  then  it  is  doubtful  if  all  is  got  rid  of ;  hence 
basic  steel  is  not  quite  so  reliable  as  that  made  by 
the  "  acid  "  process. 

When  a  basic  furnace  or  converter  is  re-lined  the 
material  of  the  old  lining  is  ground  up  and  then 
forms  the  familiar  chemical  manure  known  as 
"  basic  slag." 

However  it  may  be  made,  the  steel  when  ready  is 
run  off  into  tall  rectangular  iron  boxes  called  "  ingot 
moulds."  The  moulds  are  open  at  both  ends  and 
stand  upon  an  iron  floor.  When  set  the  steel  thus 
forms  an  ingot. 

At  this  stage  we  must  notice  the  very  wonderful 
machines  with  which  a  modern  steelworks  is  equipped. 
They  belong,  as  it  might  be  expressed,  to  the  crane 
family,  but  they  are  not  simple  cranes,  being  each 
designed  for  a  particular  operation.  Take  the  case 
of  a  "  stripper."  It  runs  on  lines  overhead,  just 
like  the  overhead  travelling  crane  to  be  seen  in  so 
many  large  works  where  heavy  things  have  to  be 
handled.  Its  duty  is  to  remove  the  moulds  from  the 
ingots  ;  for  you  must  remember  that  the  mould 
for,  say,  a  3-ton  ingot  (an  average  size)  is  itself  no 
light  weight.  So  the  stripper  lays  hold  of  the  mould 
and  pulls  it  upwards  ;  but  not  only  that,  at  the  same 
time  it  pushes  downwards  upon  the  ingot  itself, 
lifting  the  mould,  but  holding  the  ingot  down  ;  thus 
there  is  no  chance  of  the  ingot  sticking  in  the  mould 
and  being  carried  away  in  it. 


HOW  RAILS  ARE  MADE 

The  furnaces,  too,  which  we  were  considering  just 
now,  are  attended  by  a  mechanical  attendant  which 
picks  up  half  a  ton  of  materials  and  puts  it  into  the 
furnace  as  easily  as  a  man  might  throw  in  a  handful. 
When  a  quantity  of  material  needs  to  be  put  into 
the  furnace  it  is  first  placed  in  a  big,  strong,  steel 
box  ;  then  the  machine  puts  forth  its  arm  in  an 
almost  human  manner,  takes  the  box,  carries  it 
along,  thrusts  it  into  the  furnace,  turns  it  over, 
withdraws  it  empty  and  takes  it  back  again  for  more. 

At  later  stages  it  is  necessary  to  place  ingots  and 
other  heavy  masses  of  metal  in  furnaces  to  be  re- 
heated, and  here  another  type  of  "  charging  machine  " 
comes  into  play.  It  has  not  only  an  arm,  but  a  hand. 
It  can  pick  up  a  large  ingot  between  thumb  and 
finger,  place  it  in  or  take  it  out  of  a  furnace,  as  may 
be  necessary,  and  carry  it  about  from  place  to 
place. 

These  machines,  although  now  largely  constructed 
in  Great  Britain,  were  first  introduced  in  the  United 
States,  where  the  shortage  of  skilled  workmen  has 
brought  out  so  many  labour-saving  devices.  Apart, 
however,  from  the  saving  of  labour  (thereby  meaning 
saving  of  expense)  there  is  a  humanitarian  aspect. 
The  handling  of  these  great  hot  masses  by  human 
hands,  while  in  many  cases  possible,  is  work  which 
no  human  being  ought  to  be  asked  to  do.  It  is  too 
wearing,  and  to  do  it  for  long  almost  de-humanizes  a 
man.  Hence  these  wonderful  machines,  controlled 
by  man,  but  actually  worked  by  electric  motors, 
confer  a  twofold  benefit  upon  humanity. 

But  we  must  get  on.  We  have  reached  the  point 

134 


HOW  RAILS  ARE  MADE 

where  an  ingot  has  been  cast  and  the  mould  removed 
by  a  stripping  machine.  It  now  requires  to  be  re- 
heated, so  a  machine  picks  it  up  and  carries  it  away 
to  a  furnace.  This  is  in  some  cases  under  the  floor, 
so  that  the  ingot  is  just  dropped  in,  in  a  vertical 
position  ;  or  it  may  be  like  an  elaborate  form  of  the 
domestic  oven.  The  underground  type  of  furnace 
is  called  a  "  soaking  pit,"  since  the  ingot  needs  to 
be  thoroughly  soaked  through  with  heat  and  equally 
softened  throughout. 

Then  it  is  lifted  out  and  passed  through  a  suc- 
cession of  "  rolling  mills,"  machines  which  are  in 
principle  nothing  more  than  the  domestic  mangle, 
but  with  grooves  cut  in  their  iron  rollers. 

At  each  rolling  the  width  and  depth  is  reduced  and 
the  length  increased,  until  at  last  the  ingot  has  been 
rolled  down  into  the  familiar  shape  of  the  railway 
rail.  Of  course,  a  single  ingot  will  make  more  than 
one  length  of  rail,  so  that  as  the  rolling  goes  on  and 
the  bar  lengthens  it  has  to  be  cut  several  times,  an 
operation  performed  by  a  circular  saw. 

In  travelling  to  and  fro  through  the  rolling  mills 
the  steel  moves  upon  what  are  termed  "  live  rollers," 
paths  formed  of  iron  rollers  let  into  the  floor  and  all 
driven  round  by  a  motor.  Thus  the  piece  of  steel 
on  issuing  from  one  mill  travels  automatically  upon 
the  rollers  for  some  distance.  If,  then,  as  is  probable, 
it  needs  to  go  back  through  the  same  mill,  but 
through  a  different  groove  (for  there  are  a  series 
of  grooves  upon  the  rolls  in  a  single  mill)  the  rollers 
are  reversed  and  the  steel  starts  back  again,  being 
guided  by  men  with  tongs  into  the  fresh  groove. 


HOW  RAILS  ARE  MADE 

Meanwhile,  the  rolling  mill  itself  has  been  reversed, 
and  through  the  piece  of  metal  goes.  Having  finished 
at  one  mill  the  rollers  carry  it  quickly  along  to  the 
next,  and  so,  from  the  time  it  leaves  the  re-heating 
furnace,  passes  through  all  the  rolling  operations  and 
finally  emerges  as  rails,  only  a  few  minutes  is  occupied. 
Thus  we  have  traced  the  life  history  of  a  steel  rail 
from  the  ironstone  quarry  until  the  time  when  it  is 
ready  to  be  used. 


136 


CHAPTER  X 
THE  STORY  OF  THE  BRIDGES 

IT  is  a  great  mistake  to  think  that  the  big  ex- 
ceptional bridges  are  the  only  interesting  ones. 
On  the  contrary,  the  little  ones,  the  everyday 
ones,  so  to  speak,  have  an  interest  all  their  own. 

Has  it  ever  occurred  to  you  that  these  despised 
things  are  by  far  the  most  important  ?  Look  at  it 
this  way.  Take  away  the  Forth  Bridge.  The  North 
British  Railway  would  still  be  able  to  carry  on. 
Certain  trains  would  have  to  go  by  a  longer  route 
and  it  might  be  necessary  for  some  people  to  use  a 
ferry,  but  the  work  of  the  railway  could  go  on. 
Suppose,  however,  that  all  the  little  bridges  all  over 
the  line  were  to  disappear ;  the  ones  that  span 
roads  and  streams,  lanes  and  ditches  ;  the  railway 
would  then  for  all  practical  purposes  cease  to  exist. 

So  this  chapter  will  be  devoted  to  the  little  bridges. 

Railway  engineers  divide  bridges  roughly  into 
two  classes,  "  under-bridges,"  which  are  actually 
underneath  the  rails,  and  "  over-bridges,"  which 
carry  something  else  across  the  line.  Of  these  the 
under-bridges  are  naturally  the  most  interesting  to  us. 

Bridges  are  again  divided  up  in  another  way 
according  to  the  way  they  are  made.  We  will  take 
these  one  at  a  time. 


THE  STORY  OF  THE  BRIDGES 

First  of  all  there  is  the  "  plate-girder  "  bridge, 
commonly  used  to  span  ordinary  roads.  It  is  so 
called  because  it  is  built  up  of  girders  made  largely 
of  steel  plates. 

But  what  is  a  girder  ?  you  ask.  It  is  another  name 
for  a  beam,  the  custom  having  arisen  of  saying  beam 
when  it  is  of  wood,  but  girder  when  it  is  made  of 
iron  or  steel. 

A  plate-girder,  if  it  were  sawn  in  two  and  then 
looked  at  endwise,  would  look  like  a  huge  letter  I. 
The  vertical  part  is  the  web  and  the  two  horizontal 
parts  are  the  flanges.  The  strength  resides  mainly 
in  the  flanges,  the  chief  duty  of  the  web  being  to 
hold  the  other  two  together. 

The  commonest  form  of  bridge  consists  of  three 
of  these  girders  with  their  ends  supported  on  brick 
piers.  The  main  girders  lie  parallel,  shorter  ones, 
called  cross  girders,  filling  in  at  right  angles.  Upon 
the  cross  girders  longitudinal  sleepers  of  wood  are 
placed,  and  upon  them  the  rails  are  fixed.  Thus 
each  line  of  rails  runs  between  two  main  girders, 
the  middle  one  of  the  three  being  made  doubly 
strong  because  it  may  be  called  upon  to  carry  two 
trains  at  once,  while  the  outer  ones  cannot  have  to 
bear  more  than  one.  The  weight  of  the  train  falls 
firstly  upon  the  timber  sleepers,  and  is  by  them  dis- 
tributed on  to  the  cross  girders,  the  ends  of  which 
are  in  turn  held  up  by  the  main  girders. 

These  bridges  are  not  made  by  the  dozen  all 
alike,  but  each  has  a  history,  a  personality  of  its  own, 
so  to  speak.  It  commences  in  the  engineer's  drawing 
office  at  the  head-quarters  of  the  railway.  The  order 

138 


THE  STORY  OF  THE  BRIDGES 

goes  forth  to  the  steelwork  section  of  the  office  that 
a  bridge  is  required  at  a  certain  place,  and  then  an 
expert  draughtsman  sets  to  work  to  design  it.  The 
length  is  fixed  for  him  by  the  width  of  the  road,  the  load 
which  it  will  have  to  carry  is  a  string  of  the  heaviest 
locomotives  which  the  line  possesses  or  is  ever  likely 
to  possess.  It  is  very  unlikely  that  an  ordinary 
bridge  over  a  road  will  ever  be  crowded  as  full  as 
it  can  be  with  the  heaviest  engines,  but  such  a  thing 
is  possible  and  must  be  provided  for.  He  knows 
the  width  necessary  to  carry  two  lines  of  track,  and 
with  these  three  items  of  information  to  go  upon 
he  sets  to  work. 

Some  of  his  points  he  knows  by  heart.  For  example, 
experience  has  shown  that  the  most  suitable  height 
for  a  girder  is  one-twelfth  of  its  length,  so  if  there 
be  no  special  reason  to  the  contrary  he  makes  his 
main  girders  as  many  inches  in  height  as  they  are 
feet  in  length. 

The  other  details  he  works  out  by  mathematics, 
in  many  cases  using  formulae  which  are  known  to 
all  designers  of  bridges,  in  other  more  difficult  cases 
using  diagrams  wherewith  to  find  out  the  stresses 
in  certain  parts,  in  other  cases  still  calling  upon  his 
experience.  In  one  way  and  another,  then,  he  builds 
up  the  design  on  paper  until  a  carefully  finished 
drawing  is  complete. 

Ultimately  copies  of  this  drawing,  or  rather,  one 
ought  to  say  these  drawings,  for  there  are  always  a 
number  of  them  showing  different  views,  find  their 
way  to  a  works  where  the  bridge  is  to  be  made. 

The  drawings  are  made  to  some  convenient  scale, 


THE  STORY  OF  THE  BRIDGES 

but  at  the  works  the  parts  are  drawn  out  actually 
full  size,  in  chalk,  upon  a  floor.  Then  a  template 
is  made  of  each  part  in  thin  wood.  A  template 
might  be  called  a  full-sized  representation  in  wood 
of  what  the  iron  part  will  be  like  wrhen  it  is  finished. 
As  has  already  been  said,  the  web  is  made  of  plate, 
the  flanges  are  made  of  one  or  more  plates,  frequently 
one  at  the  ends  where  the  stresses  are  least,  but 
several  plates  piled  one  on  top  of  another  where  the 
stresses  are  greatest,  in  the  centre.  It  is  interesting 
to  note  that  the  stresses  in  the  flanges  and  in  the 
web  so  work  out  that  the  flanges  have  to  be  thickest 
in  the  middle,  but  the  web  has  to  be  thickest  at  the 
ends.  Then  the  flanges  have  to  be  connected  to  the 
web  by  means  of  "  angles,"  bars  which  viewed 
endwise  look  like  a  letter  L. 

There  are  limits,  of  course,  to  the  length  which 
plates  and  bars  can  be  made,  and  so  joints  have  to 
be  formed  in  places,  which  is  done  by  butting  the 
two  pieces  together  and  then  covering  the  place 
with  another  similar  plate  or  bar  of  short  length. 

Then,  again,  the  tendency  of  the  train  when  it 
passes  over  a  bridge  is  to  crumple  the  web  up,  and 
to  stiffen  it  there  are  usually  a  number  of  vertically 
placed  angles  which,  because  of  their  purpose,  are 
called  "  stiffeners." 

All  this  has  been  explained  to  show  why  the  bridge 
builders  go  to  the  trouble  and  expense  of  drawing 
the  parts  out  full  size  and  then  practically  making 
each  part  in  wood  before  it  is  made  in  iron. 

All  the  different  parts  mentioned  have  to  be  con- 
nected to  other  parts  by  rivets.  The  holes  in  one  part 

140 


THE  STORY  OF  THE  BRIDGES 

must  correspond  accurately  with  the  corresponding 
holes  in  another  part,  and  a  slight  error  in  one  lot 
of  holes  might  easily  cause  a  costly  piece  of  steel 
plate  to  be  wasted.  So  templates  are  made  first, 
just  the  correct  size,  with  every  hole  in  its  right 
position.  These  templates  can  then  be  compared 
and  tried  together,  inaccuracies  can  be  put  right  and 
adjustments  made,  so  that  when,  finally,  they  are 
copied  in  steel  the  steel  parts  can  be  relied  upon  to 
fit  each  other. 

It  needs  a  very  skilled  man  to  make  the  tem- 
plates, but  when  they  are  finished  satisfactorily  he 
can  hand  them  over  to  a  less  skilled  man,  who  will 
mark  off  the  plates  and  bars  of  steel  according  to 
the  templates,  which  bars  and  plates  will  then  pass 
on  to  less  skilled  men  still,  who  will  cut  them  and 
punch  holes  in  them  according  to  the  marks. 

The  parts,  having  been  thus  prepared,  are  then 
put  together  much  as  a  boy  puts  "  meccano  "  parts 
together,  and  fastened  temporarily  with  bolts  and  nuts. 

Work  of  this  description  used  to  be  done  mostly 
in  the  open  air,  whence  arises  the  fact  that  a  place 
where  bridges  are  made  is  often  called  still  a  bridge- 
yard.  Nowadays,  however,  the  yards  are  mostly 
covered  in,  at  any  rate  by  a  roof,  although  the  sides 
are  often  left  open.  This  enables  work  to  be  carried 
on  in  all  weathers. 

The  roof  is  always  a  high  one,  to  accommodate 
an  electric  overhead  crane.  Not  only  is  the  crane 
driven  by  electricity,  but  sometimes  it  has  a  magnet 
in  place  of  a  hook  for  lifting  the  plates  and  other 
parts  about. 

141 


THE  STORY  OF  THE  BRIDGES 

There  is  not  a  great  deal  of  other  machinery.  There 
are  usually  rows  of  drilling  machines  for  drilling  holes, 
punching  machines  for  punching  holes  (where  such 
are  permissible),  shearing  machines  for  cutting 
plates,  and  in  modern  works  a  machine  called  a 
"  cropper,"  the  function  of  which  is  to  cut  bars, 
also  various  saws. 

The  drilling  machine  is  well  known  and  needs  no 
description.  The  punching  machine  is  a  very  simple 
contrivance ;  a  steel  punch  goes  up  and  down 
continuously,  entering  at  the  bottom  of  its  stroke  a 
round  hole  in  a  steel  die  ;  the  plate  or  bar  to  be 
punched  is  just  slipped  under  it  when  it  rises,  and 
on  descending  it  pushes  a  little  round  disc  of  metal 
through  the  hole  in  the  die.  Punched  holes  are  not 
so  clean  or  so  accurately  placed  as  drilled  holes. 

The  shearing  machine  is  similar  to  the  punching 
machine,  except  that  instead  of  a  punch  there  is  a 
steel  blade  which  rises  and  falls  against  another 
blade  much  as  the  two  parts  of  a  pair  of  scissors 
move  against  each  other.  A  piece  of  steel  inserted 
between  the  two  blades  suffers  the  same  fate  as  a 
piece  of  paper  between  the  blades  of  a  pair  of  scissors. 

The  cropper  is  a  special  kind  of  shears  which  cuts 
off  bars  of  all  shapes  just  as  easily  as  the  ordinary 
shears  cuts  plates  or  flat  pieces. 

The  saws  used  are  generally  of  the  circular  variety, 
in  principle  identical  with  that  to  be  seen  in  carpentry 
shops.  A  steel  disc  with  teeth  cut  in  the  edge  turns 
round  in  contact  with  the  object  to  be  cut.  In  the 
case  of  the  metal  saw  the  speed  is  much  slower  than 
with  the  wood  saw,  and  the  saw  is  kept  cool  by  a 

142 


THE  STORY  OF  THE  BRIDGES 

constant  stream  of  soapy  water  driven  on  to  it  by  a 
little  pump. 

There  is,  however,  one  very  remarkable  machine 
sometimes  to  be  seen  in  bridgeyards  known  as  a 
high-speed  sawing  machine.  The  ordinary  saw  is 
of  hard  steel,  and  it  cuts  the  softer  steel  because  of 
its  hardness  ;  if  it  were  not  hard  it  would  not  cut ; 
moreover,  it  is  never  allowed  to  get  hot,  for  if  it  did 
it  would  become  softened  and  unable  to  do  its  work. 

In  this  strange  machine,  however,  the  saw  disc 
is  of  soft  metal,  and  it  is  allowed  to  get  as  hot  as  it 
likes.  It  is  a  well-known  fact  that  if  two  things  are 
rubbed  together  they  become  hot,  and  that  fact 
which  is  a  nuisance  in  most  saws  is  actually  turned 
to  valuable  account  in  this  one.  The  saw,  rubbing 
against  the  object  to  be  cut,  makes  it  soft  because  of 
the  heat  which  is  generated.  The  saw  itself,  whizzing 
round  in  the  air  all  the  time,  does  not  suffer  this 
softening  as  the  stationary  object  does  and  so  it  is 
able  to  rub  its  way  through.  Acting  in  this  manner 
a  disc  of  soft  steel  can  cut  through  a  piece  of  the 
hardest  steel ;  probably  the  only  case  in  which  a 
thing  cuts  something  harder  than  itself. 

But  we  must  get  on.  When  all  the  parts  have 
been  put  together  and  secured  temporarily  with 
bolts  the  latter  have  to  be  taken  out  one  at  a  time 
and  rivets  put  in  their  place.  It  may  be  wondered 
why  this  should  be  necessary,  and  the  reason  is 
twofold.  First,  a  bolt  and  nut  may  shake  loose, 
which  a  rivet  can  never  do ;  and  second,  unless 
carefully  fitted  at  considerable  cost  the  bolt  never 
quite  fills  the  holes,  whereas  a  properly  driven  rivet 

143 


THE  STORY  OF  THE  BRIDGES 

does.  It  is  easy  to  see  that  unless  the  holes  be 
entirely  filled  there  will  be  a  little  "  play,"  which 
will  get  worse  and  worse  until  the  bridge  might  even 
fail  as  the  result. 

There  are  three  methods  of  doing  this  very  im- 
portant work  of  riveting.  One  is  by  hand.  Three 
men  and  a  boy  form  a  "  squad  "  ;  the  boy  "  hots  " 
the  rivets  in  a  little  forge  and  throws  them  across 
to  one  of  the  men,  the  "  holder-up."  This  man 
inserts  each  rivet  as  he  receives  it  in  a  hole,  pushes 
it  right  in,  then  holds  it  in  with  a  heavy  hammer. 
The  other  two  men  then  attack  the  end  which 
projects  at  the  other  side,  first  of  all  hammering  it 
down  well  into  the  hole  to  ensure  the  hole  being 
filled,  then  hammering  over  what  still  projects  in 
such  a  manner  as  to  form  a  rough  head,  and  finally, 
one  man  throwing  aside  his  hammer  and  holding 
a  cup-shaped  tool  over  the  roughly  formed  head, 
which  tool  is  then  hammered  down  by  his  mate, 
a  nicely  shaped  head  results. 

The  second  method  is  by  the  use  of  a  pneumatic 
"  pistol  "  hammer,  as  described  in  connection  with 
the  visit  to  a  locomotive  works. 

The  third  way  is  to  use  what  the  workmen  call  an 
"  iron  man."  This  may  be  described  briefly  as  an 
enormous  thumb  and  finger  which,  actuated  by 
hydraulic  pressure,  just  squeeze  the  rivet  into  shape. 

The  observant  traveller  will  probably  have  noticed 
that  many  small  bridges,  such  as  those  now  under 
discussion,  have  no  cross  girders,  or  rather  that  these 
girders  take  the  form  of  steel  troughs  attached 
together  so  that  they  constitute  a  continuous  floor 

144 


THE  STORY  OF  THE  BRIDGES 

all  over  the  bridge.  This  "  trough-flooring,"  as  it  is 
termed,  is  made  by  pressing  steel  plates  in  a  powerful 
hydraulic  press. 

Of  course,  even  when  the  bridge  is  finished  in  the 
works  there  are  still  a  number  of  holes  filled  only 
with  bolts  or  else  quite  empty,  for  the  bridge  will 
have  to  go  to  its  destination  in  parts  and  be  put 
together  there,  the  final  riveting  being  done  on  the  spot. 

In  many  respects  this  placing  in  position  is  the 
most  romantic  incident  in  the  bridge's  history,  as 
the  following  actual  descriptions  will  show. 

When  a  line  is  first  made  the  bridges  are  taken 
along  in  parts  either  by  lorries  on  the  road  below, 
whence  they  are  hoisted  into  position,  or  else  they 
are  taken  along  on  the  partly  finished  line  above. 
In  either  case  the  work  can  be  done  in  the  daytime 
and  more  or  less  at  leisure.  When,  as  is  often  the 
case,  the  bridge  is  to  replace  an  older  one  in  an 
existing  line,  the  work  has  to  be  done  at  night  or  on 
Sunday  afternoon,  between  trains,  the  traffic  going 
on  all  the  time  just  as  if  nothing  were  happening. 

Success  is  then  possible  only  as  the  result  of  the 
most  careful  preparations.  Everything  has  to  be 
thought  out  beforehand  down  to  the  smallest  detail, 
for  the  lack  of,  say,  a  single  tool  might  throw  the  whole 
thing  out  of  gear,  the  favourable  interval  in  the  traffic 
might  be  missed  and  the  whole  programme  have  to 
be  postponed  for  a  week. 

The  first  bridge  that  we  will  think  of  was  on  one 
of  the  best  known  English  lines,  over  a  main  road 
connecting  two  towns  ;  it  carried  two  lines  of  railway 
with  a  fairly  continuous  traffic. 

K  145 


THE  STORY  OF  THE  BRIDGES 

The  old  bridge  was  made  of  cast  iron,  a  type  of 
construction  never  used  now,  as  cast  iron  is  not 
considered  reliable  enough  to  withstand  the  heavy 
shocks  caused  by  the  passage  of  modern  locomotives. 

The  first  thing  to  be  done,  therefore,  was  to  get 
the  old  bridge  out,  and  for  this  purpose  a  staging 
of  timber  was  built  beneath  it.  It  would  be  almost 
true  to  say  that  a  temporary  bridge  of  timber  was 
built  underneath  the  other  one.  When  this  temporary 
bridge  was  finished  wedges  were  driven  in  between 
the  cross  girders  of  the  old  bridge  and  the  temporary 
one,  so  that  after  having  carried  the  line  for  fifty 
years  or  so  those  old  cast-iron  girders  were  at  last 
relieved  of  their  load.  The  cross  girders  were  then 
disconnected  from  the  old  main  girders  until,  one 
Saturday  night,  they  were  taken  right  away. 

Saturday  night  was  chosen  because  there  was 
then  the  least  traffic.  What  there  was  was  diverted  on 
to  one  line,  so  that  for  a  few  hours  trains  were  passing 
both  up  and  down  over  the  same  rails.  To  prevent 
any  danger  of  collision,  an  official  with  a  white  band 
on  his  arm  travelled  on  every  engine  which  passed. 
He  was  a  sort  of  human  substitute  for  a  staff.  No 
train  was  allowed  to  move  on  to  the  line  unless  he 
was  on  it. 

A  big  crowd  of  workmen  were  there,  brilliant  flare 
lights  were  lit,  officials  were  there  to  represent  the 
different  departments  of  the  line.  The  travellers 
by  the  passing  trains  may  well  have  wondered  what 
was  the  matter. 

As  soon  as  the  trains  had  all  been  diverted  to  one 
line  the  men  started  to  attack  the  old  road  and  to 

146 


THE  STORY  OF  THE  BRIDGES 

pull  up  the  rails.  Then,  at  the  first  considerable 
interval  between  two  trains,  an  engine  brought  a  power- 
ful crane  and  some  trucks  along.  The  crane  quickly 
picked  up  the  big  centre  girder,  placed  it  on  a  truck 
and  then  the  line  had  to  be  cleared  for  another  train. 

Thus,  at  intervals  two  of  the  main  girders  were 
removed  and  also  the  cross  girders  from  under  one 
line,  which  was  then  re-laid  upon  the  temporary 
bridge  and  the  double  line  working  restored.  The 
whole  operation  took  less  than  six  hours. 

In  like  manner,  the  next  Saturday  night  was 
employed  in  removing  the  third  cast-iron  girder, 
and  in  addition  the  new  girders  were  brought  along 
on  trucks  and  dropped  by  two  cranes,  one  holding 
each  end,  into  position.  Two  more  Saturday  nights 
were  spent,  one  in  slipping  the  new  cross  girders  into 
position,  the  other  in  putting  in  rivets  which  could 
not  be  got  in  during  the  week. 

Then  the  temporary  wooden  structure  was  taken 
away  and  the  new  bridge  stood  finished  and  complete. 

Where  bridges  have  to  carry  only  a  light  load  the 
solid  "  web  "  is  often  replaced  by  a  light  lattice 
work.  This  form  of  structure  is  very  popular  for 
footbridges.  The  name  lattice  girder  is  applied  to  such. 

The  writer  was  once  responsible  for  the  fixing  of 
two  lattice  girders  to  carry  a  signal  cabin  above  a 
main  line  just  out  of  London.  There  were  twelve 
pairs  of  rails  under  this  bridge,  and  the  longest 
interval  between  trains  was  about  forty-five  minutes 
in  the  small  hours  of  Sunday  morning.  The  girders 
were  90  ft.  long  and  12  ft.  deep.  Since,  of  course, 
the  underside  of  them  had  to  be  high  enough  to 

14? 


THE  STORY  OF  THE  BRIDGES 

clear  the  traffic,  the  upper  edge  was  about  25  ft.  up 
in  the  air,  far  above  the  reach  of  any  travelling  crane. 
They  had,  therefore,  to  be  lifted  by  means  of  a 
"  derrick,"  a  huge  timber  40  ft.  long  and  10  ins. 
square,  with  pulley  blocks  lashed  to  its  upper  end. 

The  mere  raising  of  this  timber  was  in  itself  no 
small  matter,  but  it  was  managed  during  the  week 
by  lashing  some  blocks  to  a  conveniently  placed 
telegraph  pole.  Then  when  the  time  came  it  had  to 
be  gradually  "  walked,"  as  the  workmen  call  it,  from 
the  side  of  the  line  to  the  centre  of  the  twelve  roads. 
By  "  walking  "  a  derrick  is  meant  sliding  the  foot  of 
it  along  inch  by  inch,  while  men  let  out  some  of  the 
guy  ropes  and  pull  in  others  in  order  to  keep  it  upright. 

Eventually  the  rope  was  attached  to  one  of  the 
girders,  passed  up  to  the  pulley  blocks  at  the  top  of 
the  derrick,  down  again  to  a  block  at  the  foot  of  the 
derrick  and  then  to  a  locomotive. 

This  hoisting  by  means  of  a  locomotive,  particularly 
in  the  middle  of  the  night,  is  an  exciting  business. 
The  foreman  gives  the  word,  the  engine  starts  to 
move  and  so  to  pull  the  rope,  things  creak,  chains 
suddenly  settle  down  to  their  various  jobs  with  a 
crack,  you  see  the  girder  rising  from  the  ground,  and 
inevitably,  especially  if  you  are  in  any  sense  re- 
sponsible, the  thought  comes,  "  suppose  something 
broke."  All  concerned  breathe  more  freely  when 
the  thing  is  at  last  securely  fixed  in  its  place. 

When  a  pair  of  girders  have  to  be  lifted  like  this 
(and  there  are  always  two)  the  second  one  is  worse 
than  the  first,  because  the  first  gets  in  the  way.  So 
it  all  has  to  be  planned  out  mentally  beforehand, 

148 


THE  STORY  OF  THE  BRIDGES 

or  on  paper,  to  make  quite  sure  that  everything  will 
come  right. 

It  is  not  only  light  bridges  which  are  of  the  lattice 
structure.  There  is  one,  for  instance,  near  where 
these  words  are  being  written,  across  a  very  wide 
road  and  carrying  the  heaviest  main  line  traffic, 
which  is  of  the  lattice  type. 

The  reason  for  this  is  that  it  is  too  big  for  a  simple 
web  of  plates.  Plates  are  not  made  large  enough  to 
work  conveniently,  and  even  if  they  were  it  would 
be  found  more  economical  in  such  a  large  bridge  to 
place  the  plates,  reinforced  by  angles,  in  a  lattice 
arrangement  rather  than  as  in  plate-girders. 

Thus  we  may  say  that  for  under-bridges  of  small 
or  moderate  size  the  plate-girder  bridge  is  best,  for 
very  large  bridges  or  for  bridges  to  carry  light  loads 
the  lattice  form  is  best. 

There  are  many  cases,  particularly  in  large  bridges, 
where  the  upper  side  of  the  girder  is  given  the  form 
of  an  arch.  Those  are  spoken  of  as  "  bowstring  " 
girders,  from  their  similarity  to  the  bow  of  an  archer. 

The  science  of  bridge  design  is  so  well  understood 
now  that  very  often  bridges  are  not  tested,  but  in 
some  special  cases  they  are  tried  in  the  following 
simple  manner.  A  wooden  rod  is  fixed  in  some 
convenient  way  against  the  centre  of  the  bridge  and 
a  mark  is  made  upon  it  showing  the  level  of  the  bridge. 
Then  some  heavy  locomotives  are  made  to  stand  upon 
the  bridge  and  the  amount  of  bending  which  takes  place 
is  noted.  Very  seldom  is  anything  found  to  be  wrong. 

So  when  you  go  on  a  railway  journey,  the  last  thing 
you  need  be  anxious  about  is  the  safety  of  the  bridges. 


CHAPTER  XI 
HOW  SINGLE  LINES  ARE  WORKED 

BY  "  single  "  line  is  meant  not  that  the  trains 
run  on  one  rail,  as  has  been  proposed  in  the 
"  mono-rail "  schemes,  but  that  trains  run 
both  ways  along  a  single  pair  of  rails. 

It  is  evident  that  such  a  line  has  dangers  of  its 
own  far  more  terrible  in  their  possibilities  than  the 
risks  of  ordinary  double  lines. 

The  obvious  way  to  remove  these  special  risks  is 
to  make  the  lines  double,  to  have  one  pair  of  rails 
for  up  trains  and  one  for  down  trains,  but  there  are 
many  cases  where  the  amount  of  traffic  does  not 
justify  such  a  large  expense. 

There  are  places,  even  in  so  densely  peopled  a 
country  as  Great  Britain,  where  only  a  few  trains 
are  needed  between  two  points,  yet  those  few  trains 
may  be  quite  important  ones.  In  such  cases  a  single 
line  is  quite  sufficient,  and  it  would  be  simply  a  waste 
to  make  it  double.  Some  other  means,  therefore, 
has  had  to  be  adopted  to  ensure  safety. 

In  the  first  place,  nearly  every  single  line  has  short 
lengths  at  convenient  intervals  where  the  line  is 
doubled  in  order  to  afford  passing  places  where  one 
train  may  pass  another.  The  problem,  in  those 
cases,  is  to  ensure  there  shall  not  be  more  than  one 

150 


HOW  SINGLE  LINES  ARE  WORKED 

train  at  a  time  in  the  space  between  two  passing 
places,  at  all  events  not  in  the  same  direction. 

The  only  exceptions  are  short  branches,  too  short 
to  need  any  passing  place,  where  safety  is  ensured  by 
having  only  one  engine  to  work  all  the  trains  on 
that  branch.  That  is  perhaps  the  simplest  method 
of  all,  but  unfortunately  it  cannot  be  applied,  except 
in  these  comparatively  few  cases. 

An  arrangement  often  resorted  to  when,  through 
an  accident  or  other  emergency,  a  piece  of  line  has 
to  be  worked  as  "  single,"  is  to  have  a  "  pilotman," 
as  he  is  termed,  a  special  official  told  off  for  the 
purpose  and  distinguished  by  a  band  round  his  arm  ; 
a  train  is  only  allowed  to  move  on  to  the  single  line 
when  this  man  is  on  the  engine. 

The  same  principle  underlies  the  "  staff "  system, 
which  was  the  first  system  to  be  used  on  single  lines 
generally. 

Under  this  there  is  for  each  section  of  single  line 
a  special  "  staff,"  generally  a  metal  rod,  clearly 
marked  in  some  way  with  the  name  of  the  section 
to  which  it  applies.  The  rule,  then,  is  that  upon  no 
account  whatever  may  a  driver  move  a  train  on  to 
the  section  until  he  has  the  staff  with  him. 

At  each  passing  place  he  gives  up  the  staff  for 
the  section  he  has  just  left  to  the  stationmaster  or 
signalman,  and  receives  in  exchange  the  staff  for 
the  section  which  he  is  about  to  enter. 

It  will  be  seen  at  once  that  this  arrangement  is  all 
right  so  long  as  the  trains  alternate  regularly,  first 
an  up  train,  then  a  down  train,  all  through  the  day. 
But  suppose,  as  must  often  happen,  that  several 

15* 


HOW  SINGLE  LINES  ARE  WORKED 

trains  follow  each  other  in  the  same  direction  without 
one  in  between  to  bring  the  staff  back,  what 
then? 

This  is  overcome,  in  the  following  manner,  by  the 
"  staff  and  ticket  "  system. 

At  each  passing  place  there  is  not  only  a  staff,  but 
a  box  containing  certain  printed  tickets.  The  staff 
has,  on  one  end  of  it,  a  projection  which  forms  a  key, 
by  means  of  which  this  box  can  be  opened.  If, 
therefore,  a  signalman  or  stationmaster  knows  that 
there  will  be  two  or  more  trains  in  the  same  direction 
before  one  comes  the  other  way,  he  may  use  the 
staff  to  unlock  the  box  and  take  out  a  ticket.  This 
he  hands  to  the  driver  of  the  first  train.  He  does 
not  give  him  the  staff  under  these  conditions  ;  he 
shows  the  staff  to  the  driver,  but  gives  him  the  ticket. 
Then  the  driver  may  proceed. 

If  there  are  more  than  two  trains  going  in  the  same 
direction,  the  driver  of  the  second  one  is  also  shown 
the  staff  and  given  a  ticket,  and  so  on  until  the  last 
of  the  series.  To  him  the  staff  is  given  in  the  ordinary 
way. 

That  arrangement  is  all  right  up  to  a  point.  It 
has  the  disadvantage  that  a  train  may  enter  a  section 
before  the  preceding  one  is  clear  away,  and  so  it 
has  to  be  worked  in  conjunction  with  telegraphic 
messages  between  the  two  ends  of  the  section,  like 
the  block  signalling  on  an  ordinary  double  line.  It 
also  has  the  disadvantage  that  if  a  train  turns  up 
unexpectedly  at  the  commencement  of  a  section 
when  the  staff  happens  to  be  at  the  other  end  it  has 
either  to  wait  a  long  time  for  a  train  to  bring  the 

152 


HOW  SINGLE  LINES  ARE  WORKED 

staff,  or  for  a  man  to  bring  it,  either  on  foot  or  on 
horseback. 

Needless  to  say,  a  system  with  so  great  a  draw- 
back as  this  was  not  allowed  to  prevail  for  long  before 
someone  found  a  means  of  avoiding  the  difficulty. 
Hence  arose  the  "  tablet  "  system,  the  system  which, 
in  one  form  or  another,  is  now  used  on  single  lines 
all  over  the  world. 

In  this  system  there  are  two  instruments  for  each 
section  of  single  line,  one  at  each  end,  connected 
together  by  wires,  like  two  telegraph  instruments. 
They  are  exactly  alike,  consisting  externally  of  a 
wooden  cabinet  with  certain  knobs  and  indicators 
attached,  and  together  they  contain  a  number  of 
tablets,  usually  thirty  or  thereabouts. 

To  understand  how  this  works  it  is  simplest  to 
regard  the  two  instruments  as  forming  really  one, 
linked  together  by  the  wire,  and  the  construction  is 
such  that  only  one  tablet  can  be  out  at  a  time.  As 
soon  as  one  has  been  taken  out  all  the  others  at  both 
ends  are  securely  locked  up,  and  so  they  remain 
until  the  one  has  been  put  back.  A  tablet  may  be 
taken  out  at  either  end  of  the  section  and  put  back 
at  either  end,  but  there  can  only  be  one  out  at  a  time. 

This  is  then  given  to  the  driver  as  a  sign  that  he 
may  proceed,  and  he  must  not  proceed  without  it. 

The  tablets  are  little  pieces  of  metal  carefully 
marked  to  show  what  section  they  belong  to  and 
also  numbered,  so  that  each  one  can,  if  necessary, 
be  distinguished  from  any  other.  They  also  vary 
slightly  in  shape,  so  that  it  is  impossible  to  put  one 
into  the  wrong  instrument. 


HOW  SINGLE  LINES  ARE  WORKED 

If  the  flow  of  traffic  is  mainly  in  one  direction  the 
result  is  that  the  tablets  accumulate  at  one  end,  and 
to  deal  with  this  it  is  arranged  that  when  the  number 
at  either  end  has  fallen  to  a  certain  limit,  say  five, 
the  signalman  advises  the  telegraph  linesman,  who 
thereupon  sets  it  right.  This  man  is  provided  with 
a  key,  by  means  of  which  he  can  take  out  the  surplus 
tablets  from  the  end  where  there  is  an  accumulation. 
He  can  only  do  this  subject  to  very  special  conditions. 
He  has  to  make  a  list  of  the  tablets  which  he  takes 
out,  noting  the  distinguishing  number  on  each  in  a 
book  which  he  carries  for  the  purpose.  This  has  to 
be  countersigned  by  the  signalman  at  the  box  where 
he  takes  them  out.  He  must  on  no  account  let  them 
out  of  his  possession  until  he  places  them  in  the 
instrument  at  the  other  end,  and  when  he  does 
that  he  must  get  the  signature  of  the  signalman 
there.  At  first  sight  it  seems  that  the  mere  possi- 
bility of  any  man  being  able  to  take  out  a  handful 
of  tablets  at  once  is  a  source  of  danger,  but  the 
strict  regulations  and  the  exchange  of  signatures 
with  the  two  signalmen  entirely  remove  this. 

But  we  have  not  yet  reached  the  last  of  the  wonder- 
ful precautions  embodied  in  this  system.  There 
are  signals  at  the  passing  places  on  a  single  line,  just 
like  those  on  a  double  line,  and  a  driver  has  to  observe 
these  even  if  he  has  a  tablet  in  his  possession.  This 
is  intended  to  guard  against,  among  other  things, 
a  driver  thoughtlessly  proceeding  without  the 
tablet. 

On  some  lines  these  signals  are  normally  locked  at 
danger  and  can  only  be  unlocked  by  using  the  tablet 

'54 


HOW  SINGLE  LINES  ARE  WORKED 

as  a  key.  Thus  if  the  signal  is  lowered  it  is  a  proof 
that  the  free  tablet  is  at  that  end.  There  we  have  a 
species  of  inter-locking  between  the  tablets  and  the 
signals. 

Something  similar  is  done  where  there  are  points 
on  a  single  line.  It  will  be  clear  to  anyone  that  there 
must  be  places  where  the  presence  of  a  brickfield,  a 
stone  quarry  or  something  of  that  kind  may  necessi- 
tate a  siding  in  the  middle  of  a  stretch  of  single  line. 
How,  then,  can  it  be  ensured  that  the  points  of  such 
a  siding  are  always  properly  set  for  an  approaching 
train  ?  This  is  how  it  is  done. 

A  train  comes  along  which  has  trucks  to  put  into 
the  siding,  or  which  has  to  call  to  fetch  trucks  out. 
Of  course,  the  driver  has  the  tablet  with  him.  When 
he  approaches  the  points  he  stops,  and  the  guard 
gets  down  and  to  him  the  driver  hands  the 
tablet. 

Now  the  points  are  normally  locked  in  the  correct 
position  for  trains  to  run  straight  along  upon  the 
main  line,  so  the  guard  has  first  to  unlock  them. 
To  do  this  he  raises  a  spring,  pulls  out  a  slide  from 
the  locking  mechanism,  puts  the  tablet  into  a  cavity 
in  the  slide  and  then  pushes  it  back. 

The  points  are  now  unlocked,  but  he  has  lost  the 
tablet.  It  is  the  tablet  now  which  is  locked  up,  for 
when  once  he  has  moved  the  points  for  the  train  to 
go  into  the  siding  he  cannot  pull  the  slide  out  again. 
All  is  safe,  therefore,  and  no  other  train  can  approach 
from  either  direction  while  the  points  are  open. 

Having  finished,  the  guard  restores  the  points  to 
their  normal  state,  when,  and  not  before,  he  can 


HOW  SINGLE  LINES  ARE  WORKED 

pull  the  slide  out  again  and  regain  possession  of  the 
tablet.  The  points  must  be  right,  therefore,  before 
another  train  can  pass. 

Having  received  the  tablet  back  from  the  guard 
the  driver  can  then  proceed  upon  his  way. 

The  tablets  are  usually  placed,  when  in  use,  in  a 
leather  pouch  with  a  large  loop-shaped  handle.  The 
purpose  of  this  is  to  enable  the  man  on  the  engine  to 
catch  it  upon  his  arm  as  he  passes  a  passing  place, 
without  having  to  stop.  In  some  places  this  idea  is 
carried  even  farther,  and  the  bag  is  hung  upon  a 
post  beside  the  line,  so  arranged  that  a  projection 
upon  the  engine  catches  it,  in  which  case  a  fast  train 
can  run  past  a  tablet  exchanging  point  without 
stopping  or  even  slowing  up  materially.  By  similar 
means  the  tablet  for  the  previous  section  can  be 
hung  from  the  engine  and  left,  after  passing,  hanging 
upon  a  projection  upon  the  post,  so  that  the  complete 
exchange  of  one  tablet  for  another  is  practically 
automatic. 

As  has  been  pointed  out  already,  a  line  may  be 
single  because  few  trains  travel  over  it,  yet  some 
of  those  few  trains  may  be  quite  important  ones, 
which  it  is  desirable  to  run  as  fast  as  possible,  so 
that  this  tablet -changing  device  is  very  valuable. 

There  is  a  modification  of  the  tablet  system  in 
use  at  some  points,  called  the  "  permissive  tablet 
system."  This  is  specially  useful  where  a  section  is 
a  long  one,  and  it  may  be  desirable  to  let  one  train 
follow  another  fairly  closely,  at  a  shorter  distance 
apart  than  the  length  of  that  section.  This  would 
be  likely  to  occur  upon  a  line  serving  a  growing 


HOW  SINGLE  LINES  ARE  WORKED 

district,  where  the  conditions  are  being  approached 
which  will  make  it  worth  while  to  double  it. 

In  such  a  case  the  permissive  tablet  arrangement 
permits  a  signalman  who  holds  an  ordinary  tablet 
to  obtain  another  one  of  a  different  kind — a  "  per- 
missive tablet." 

Having,  then,  several  trains  to  pass  through 
quickly  in  the  same  direction  he  first  obtains  the 
ordinary  tablet.  This  enables  him  to  obtain  "  per- 
missive "  tablets  for  the  earlier  trains,  yet  prevents 
a  train  entering  the  section  from  the  other  end.  The 
last  of  the  series  takes  the  ordinary  tablet. 

This,  it  will  be  seen,  is  very  similar  to  the  staff 
and  ticket  arrangement. 

The  later  trains  of  a  series  are,  of  course,  warned 
to  go  carefully,  prepared  to  stop  short  of  any  obstruc- 
tion. 

There  is  another  system  called  the  "  electric  staff  " 
system,  but  this  is  in  all  essential  features  similar 
to  the  tablet. 


'57 


CHAPTER  XII 
RAILWAY  SIGNALS 

THE  earliest  signals  were  formed  by  a  man's 
arm.  We  see  the  same  thing  even  now 
when  a  guard  starts  a  train  from  a  station. 
Hence  it  was  quite  natural  that  when  a  permanent 
signal  mounted  upon  a  post  came  into  use  it  took 
the  form  of  an  arm  projecting  out  from  the  post 
horizontally. 

At  first  these  arms  had  three  positions,  and  it  is 
a  very  interesting  fact,  as  we  shall  see  later,  that 
after  being  abandoned  and  out  of  use  for  a  great 
many  years,  the  three-position  signal  has  come  into 
vogue  again  on  certain  lines. 

These  three  positions  were  "  horizontal,"  meaning 
"  stop,"  half  down,  at  an  angle  of  about  forty-five 
degrees,  indicating  "  go  on,  but  keep  a  careful  look 
out,"  and  "  vertical,"  which  showed  that  the  line 
ahead  was  clear  and  that  the  driver  might  go  on  with 
confidence. 

The  arms  were  then  operated  by  levers  at  the  foot 
of  the  post,  and  the  man  often  had  nothing  more 
than  a  shelter,  as  a  "  fogman "  has  nowadays. 
There  was  no  need  for  a  cabin  then,  apart  from  the 
comfort  of  the  signalmen  (and  such  things  were  not 
thought  much  about  in  those  days),  because  there 

158 


RAILWAY  SIGNALS 

were  no  instruments  then.  The  signalman  worked 
to  his  watch  and  nothing  more. 

When  a  train  passed  him  he  noted  the  time  ;  after 
a  certain  number  of  minutes  had  elapsed  he  put  the 
signal  half-down  ;  after  the  lapse  of  a  certain  further 
interval  he  let  it  right  down.  That  was  all  he  did, 
and  while  it  was  thought  at  the  time  to  be  sufficient 
we  can  easily  see  how  easy  it  would  be  under  such 
conditions  for  accidents  to  happen. 

As  a  matter  of  fact,  little  else  was  possible  at  that 
time,  for  the  electric  telegraph  had  not  been  in- 
vented and  modern  signalling  is  based  almost  entirely 
upon  the  use  of  the  telegraph.  However  railways 
would  have  been  worked  if  the  telegraph  had  not 
come  along  just  in  the  nick  of  time,  is  an  interesting 
subject  for  thought. 

Let  us  trace  the  development  of  the  modern 
signalling  systems  from  these  simple  beginnings. 

At  first  we  may  picture  to  ourselves  the  addition 
of  a  simple  "  needle  "  telegraph  instrument  to  the 
signalman's  outfit,  enabling  him  to  keep  in  touch 
with  his  colleagues  on  either  side  and  to  learn  from 
them  when  trains  duly  reached  them.  With  the 
installation  of  these  instruments  came  the  need  for 
better  shelter,  leading  eventually  to  the  comfortable 
and  well-fitted  cabin  of  to-day. 

The  use  of  the  telegraph  led  almost  inevitably  to 
the  invention  of  the  "  block  "  system.  A  signalman 
was  instructed  not  to  lower  the  signal  for  a  train  to 
proceed  until  he  had  heard  on  the  telegraph  that 
the  previous  one  had  safely  reached  the  next 
signals.  There  you  have  the  basis  of  the  "  block 


RAILWAY  SIGNALS 

system,"  the  chief  cause  of  the  safety   of  modern 
trains. 

Another  thing  which  happened  soon  after  the 
signal  was  first  installed  in  its  primitive  simplicity 
was  the  discovery  of  interlocking.  Who  actually 
invented  this  is  somewhat  of  a  mystery,  but  the 
following  story  is  given  on  the  authority  of  an 
official  of  one  of  the  great  British  railways. 

At  a  certain  small  station  there  was  a  level  crossing. 
This  was  protected  by  a  tall  signal  worked  by  a 
lever  at  its  base.  When  the  gates  were  open  to  road 
traffic,  and  therefore  closed  across  the  railway,  this 
signal  was  supposed  to  be  kept  at  danger.  When 
the  gates  were  shut  to  the  road  and  open  to  the 
railway,  then,  and  only  then,  was  the  signal  allowed 
to  be  lowered.  It  was  the  stationmaster's  duty  to 
supervise  this  and  see  that  it  was  done  correctly. 

Now  a  train  used  to  come  through  that  station 
every  evening  at  nine  o'clock.  It  did  not  stop,  so 
that  the  stationmaster  had  no  need  to  be  there, 
except  to  look  after  the  working  of  the  signal. 

But  nine  o'clock  was  the  hour  when  the  excellent 
stationmaster  liked  to  have  his  supper,  so  that  the 
call  of  supper  and  the  call  of  duty  came  into  conflict. 

Evidently  this  official  was  an  ingenious  man,  for 
he  contrived,  after  a  while,  to  have  his  supper  at 
the  desired  time  without  in  any  way  endangering 
the  train  or  anyone  else. 

He  noticed  that  if  he  fixed  a  stout  bar  to  the  gate 
in  a  certain  way,  it  would  prevent  the  signal  being 
worked  ;  it  would  project  itself  just  above  the  lever, 
so  that  it  could  not  be  moved. 

160 


By  permission  of  the] 


[Great  Western  Railway. 


THE  NEWEST  KIND  OF  SIGNAL. 

"  Three-position  "  signals  are  now  coming  into  extensive  use.  The  one  on  the 
right  is  at  danger  ;  the  one  on  the  left  is  at  "  proceed  with  caution."  To  indicate 
safety  the  arm  goes  straight  up.  The  corresponding  lamps  are  red,  yellow  and 
green.  The  arm  is  worked  by  an  electric  motor  in  an  iron  case  fixed  to  the  post. 


RAILWAY  SIGNALS 

This,  of  course,  happened  only  when  the  gate  was 
in  one  certain  position,  namely,  open  to  the  road. 

Thus,  so  long  as  the  gates  were  open  to  the  road  and 
closed  against  the  train  the  signal  could  not  possibly 
be  lowered.  Before  it  could  be  lowered  the  gates 
had  to  be  opened  for  the  train.  So  the  good  station- 
master  was  able  to  have  his  supper,  knowing  that  his 
assistant  whom  he  had  left  in  charge  could  not  make 
a  mistake. 

Even  if  that  be  not  the  true  story  of  the  origin  of 
"  interlocking  "  it  is  quite  .a  good  story  and  serves 
to  indicate  very  clearly  what  "  interlocking  "  really  is. 

To-day  that  principle  is  applied  to  all  sets  of  signals. 
All  those  which  need  to  be  operated  in  connection 
with  others  are  so  interlocked  with  them  that  they 
cannot  be  pulled  except  in  certain  permissible  com- 
binations. Indeed,  on  some  lines  the  apparatus  in 
one  cabin  actually  locks  and  unlocks  that  in  another 
by  electricity.  But  to  that  we  will  return  a  little 
later. 

So  far  we  have  traced  the  growth  of  the  two  great 
underlying  principles  of  signalling,  first  the  "  block 
system,"  under  which  it  is  decreed  that  not  more 
than  one  train  shall  be  between  two  signal  cabins 
at  the  same  moment,  and  second,  that  the  apparatus 
in  any  one  cabin  shall  be  so  interlocked  that  a  careless 
signalman  simply  cannot  lower  contradictory  signals. 

To  both  of  these  principles  there  is  added  another 
one,  without  which  neither  would  be  perfect.  This 
third  principle  is  that  everything  shall  be  so  arranged 
that  failure  of  apparatus  shall  stop  traffic  rather 
than  endanger  it. 

L  161 


RAILWAY  SIGNALS 

This  is  well  illustrated  by  the  way  a  signal  is 
fitted  up.  Everyone  is  familiar  with  the  heavy  weight 
on  the  end  of  a  lever  to  be  seen  at  the  foot  of  every 
signal  post.  The  purpose  of  that  is  to  keep  the  wire 
taut.  The  signal  is,  of  course,  operated  by  a  wire 
from  the  signal  cabin,  and  in  order  to  lower  the 
arm  the  wire  has  to  be  pulled.  One  is  apt  to  think 
that  the  signalman  lets  the  arm  fall  when  the  line 
is  clear,  but  that  is  not  the  case  ;  he  actually  pulls 
it  down  by  pulling  up  the  balance  weight. 

Thus,  should  the  wire  break,  the  arm  flies  to 
danger.  Indeed,  the  principle  is  carried  still  further 


OOVN  DOWN   HOME 

STARTING  DieTAHl 

Fig.  9. — DIAGRAM  SHOWING  THE  NAMES  or  SIGNALS  AT 
A  WAYSIDE  STATION. 

than  that,  for  the  arm  itself  is  actually  loaded  at 
its  short  end  so  that  in  the  event  of  the  rod  connecting 
arm  and  balance  lever  becoming  detached,  a  most 
unlikely  thing,  the  arm  itself  will  go  to  danger. 

This  result  is  attained  by  making  the  iron  frame 
which  carries  the  coloured  glass  heavier  than  it 
need  otherwise  be. 

On  some  lines  nowadays  the  same  effect  is  attained 
by  making  the  signal  arm  go  upwards  instead  of 
down  to  indicate  line  clear. 

Generally  speaking,  there  is  a  signal  cabin  at 
every  station,  and  for  each  line  there  are  generally 
three  signals.  Near  to  the  station  on  the  side  at 

162 


RAILWAY  SIGNALS 

which  the  train  enters,  there  is  one  called  the  home 
signal.  It  is  generally  on  the  top  of  a  tall  post,  for 
it  is  the  most  important  of  the  signals  and  may 
need  to  be  seen  from  a  considerable  distance  by 
trains  which  are  not  stopping  at  the  station. 

At  the  other  end  of  the  station  there  is  a  second 
signal,  usually  on  a  short  post,  called  the  starting 
signal.  The  third  is  the  "  distant  "  signal,  and  its 
place  is  about  800  yards  back,  behind  the  home 
signal.  It  is  generally  distinguished  by  having  a 
V-shaped  notch  cut  out  of  the  end  of  the  arm.  At 
a  distant  signal  trains  do  not  stop,  for  it  is  only  an 
indicator  to  warn  an  approaching  train  if  the  home 
signal  is  against  it.  Thus,  if  a  distant  signal  is  up, 
or  "  on  "  as  the  railwayman  calls  it,  the  driver  does 
not  stop,  but  slows  down  and  keeps  his  train  in  hand 
ready  to  stop  at  the  home  signal  if  need  be. 

The  purpose  of  the  starting  signal  is  this  :  A  train 
is  approaching  a  station  where  it  is  booked  to  stop, 
but  the  section  ahead  is  not  clear,  for  the  preceding 
train  has  not  yet  passed  the  next  cabin  ;  the  signal- 
man, therefore,  keeps  his  home  signal  up  until  the 
train  has  nearly  stopped  ;  then  he  lowers  it  and 
allows  the  train  to  draw  slowly  ahead  up  to  the  starting 
signal.  But  for  the  latter  he  would  have  to  keep  it 
standing  outside  the  station  until  the  section  ahead 
had  become  clear. 

Where  there  is  a  long  distance  between  two  stations 
there  is  often  an  intermediate  signal  cabin ;  there 
are  also  cabins  at  junctions  where  there  are  no 
stations,  but  every  cabin  has  a  similar  set  of  signals 
for  each  line  and  for  branches  if  there  be  any. 

163 


RAILWAY  SIGNALS 

Moreover,  every  cabin  is  in  electrical  communication 
with  the  cabins  on  either  side  of  it,  and  is  itself  full 
of  wonderful  devices  of  a  mechanical  nature  to 
prevent  the  signalman  making  a  mistake. 

At  junctions  or  where  there  are  cross-over  roads 
or  sidings,  the  points  as  well  as  the  signals  are  worked 
from  the  cabin,  and  points  and  signals  are  inter- 
locked so  that  they  can  only  be  worked  properly 
together. 

Let  us,  in  imagination,  take  a  look  inside  an 
ordinary  typical  signal  cabin.  Its  main  feature  is 
the  row  of  strong  steel  levers.  These  are  about  the 
right  height  for  a  man  to  pull  easily,  as,  indeed,  they 
need  to  be,  for  a  lever  which  operates  distant  points 
calls  for  some  good  muscular  effort  to  move  it. 

The  levers  are  pivoted  about  the  level  of  the  floor, 
and  their  upper  halves  are  guided  by  a  framework 
of  iron  with  slots  in  which  they  can  move  to  and 
fro.  Each  arm,  also,  is  fitted  with  a  catch  which 
holds  it  in  position,  except  when  the  man  is  ready 
to  move  it. 

Above  the  row  of  levers  is  a  shelf,  the  "  instrument 
shelf,"  upon  which  stand  all  the  marvellous  electrical 
devices  by  which  the  signalman  is  assisted  in  his  work. 

Every  instrument  has  its  label  setting  out  clearly 
what  it  is  for,  and  every  lever  has  a  little  tablet 
showing  the  signal  or  switch  to  which  it  relates. 
The  levers  are  grouped  together,  so  that  all  those 
likely  to  be  pulled  at  the  same  time  are  near  at 
hand,  and  they  are  further  distinguished  from  one 
another  by  their  colour,  signals  being  one  colour 
and  points  another. 

164 


RAILWAY  SIGNALS 

Below  the  floor  is  the  interlocking  apparatus, 
one  of  the  most  beneficent  pieces  of  machinery  ever 
invented.  To  it  we  will  now  turn  our  attention. 

The  basis  of  it  is  an  oblong  block  of  iron  as  long  as 
the  row  of  levers  and  of  a  -»width  which  varies  in 
different  cabins,  but  may  be  put  as  somewhere 
about  a  foot. 

In  the  upper  surface  of  this  "  locking  trough,"  as 
it  is  called,  there  are  a  number  of  grooves,  some 
long,  running  lengthwise,  and  some  short,  running 
crosswise  at  right  angles  to  the  first. 

In  each  of  the  short  grooves  there  fits  a  steel 
slide  smooth  of  surface,  and  of  such  a  size  that  it 
fits  nicely,  and  is,  therefore,  free  to  slide  endwise, 
but  without  shake. 

It  is  not  possible  to  describe  this  intelligibly 
merely  in  words  ;  the  aid  of  a  series  of  three  diagrams 
is  necessary. 

In  the  first  of  them  we  have  a  representation  of  a 
fragment  of  a  locking  trough  and  two  short  pieces 
of  slide.  Everything  is  cut  away,  except  what  is 
necessary  to  show  clearly  how  this  mechanism  works. 
Slide  A  it  will  be  noticed  has  a  notch  cut  in  its  right- 
hand  side,  while  slide  B  has  a  similar  notch  in  its 
left  side.  In  one  of  the  longitudinal  grooves  there 
lies  a  short  piece  of  steel  called  a  lock,  and  in  the 
illustration  it  is  shown  with  one  end  fitting  into  the 
notch  in  slide  A,  while  its  other  end  is  close  up 
against  the  edge  of  slide  B.  Now  supposing  someone 
were  to  try  to  pull  slide  A,  he  would  find  it  impossible 
to  do  so,  because  of  the  lock  engaging  in  the  notch. 

On  the  other  hand,  slide  B  is  quite  free.  Suppose 

165 


RAILWAY  SIGNALS 


it  be  pulled,  so  that  we  get  the  state  of  things  shown 
in  the  second.  Now  A  is  free,  because  when  it  is 
pulled  the  lock  is  able  to  slide  to  the  right  into  the 
notch  in  B. 

GROOVE  FOR  SJL1D1 


GROOVE 
FOR      LOCK 


LOCK 


Fig.  10. — This  diagram  shows  the  beautifully  simple  means 
by  which  the  signal  levers  are  made  to  lock  and  unlock  each 
other,  so  that  a  signalman  cannot  make  a  mistake. 

Slide  A  cannot  be  pulled  because  of  the  lock,  but  slide  B 
is  quite  free. 

Suppose  slide  B  to  be  pulled,  then  we  get  the  position 
shown  in  the  next  diagram. 

Thus  we  get  the  position  shown  in  the  third,  where 
slide  A  is  free,  but  slide  B  is  locked,  exactly  the  reverse 
of  what  we  started  with.  Therefore,  slide  A  must 

166 


RAILWAY  SIGNALS 


be  restored  to  its  first  position  before  slide  B  can  be 
used  again. 

This  is,  of  course,  merely  a  simple  illustration  of  the 
principle.  In  actual  application  the  various  inter- 
locking combinations  are  very  complicated,  and  the 
result  of  the  most  careful  thought  and  consideration, 
but  however  complicated  they  may  be,  when  once 
the  necessary  notches  have  been  made  in  the  slides 
and  the  necessary  locks  put  in  position,  the  working 
of  the  apparatus  is  beautifully  simple.  It  is  so  simple 


LOCK 


U)CK 


Fig.  11. 

This  shows  how  the  pulling  This  shows  how  the  pulling 

of  slide  B  unlocks  elide  A.  of  A  locks  B  in  the  pulled 

position. 

that  failure  is,  humanly  speaking,  an  impossibility, 
and  the  whole  is  so  robust  and  strong  that  no  signal- 
man, no  matter  how  muscular  he  may  be,  can  possibly 
pull  "  off  "  a  signal  which  he  ought  not  to  do. 

The  lower  end  of  each  signal  lever  is  connected 
to  a  slide,  so  that  the  slide  controls  the  movement  of 
the  lever  absolutely. 

As  an  illustration  of  the  effect  of  interlocking  we 
may  take  the  case  of  a  junction  where  a  branch  goes 
off  to  the  right  in  a  "  down  "  direction.  A  down 

167 


RAILWAY  SIGNALS 

train  in  order  to  pass  on  to  the  branch  will  then  have 
to  cross  the  "up  "  line,  and  unless  great  care  were 
exercised  that  point  would  be  a  source  of  great 
danger,  for  a  "  down  "  train  to  the  branch  might 
collide  with  an  "  up  "  train  on  the  main  line. 

In  such  a  case  it  is  so  arranged  that  the  points 
cannot  be  set  for  the  "  down  "  train  to  cross  the 
"  up  "  line  unless  all  the  signals  controlling  the  "  up  " 
line  are  at  danger,  and  further,  as  soon  as  the  points 
are  so  set,  it  is  impossible  for  those  signals  to  be 
lowered.  The  interlocking  apparatus  effectually 
prevents  any  error  on  a  point  like  that. 

All  points  the  tongues  of  which  point  in  the 
direction  from  which  a  train  reaches  them  are 
called  "  facing  points."  For  example,  those  on  the 
"  down  "  line  at  our  imaginary  junction  are  "  facing 
points,"  but  those  on  the  "  up "  side  would  be 
"  trailing  points."  It  is  quite  clear  that  the  former 
are  much  the  more  dangerous,  for  if  not  properly 
set  and  tightly  held  they  might  easily  throw  a  train 
off  the  line,  whereas  if  trailing  points  are  not  correct, 
the  train  itself,  in  passing  over  them,  will  tend  to 
put  them  right.  Great  care  is  therefore  taken  to 
ensure  the  proper  working  of  facing  points.  In  the 
first  place,  there  is  one  lever  in  the  cabin  for  the 
purpose  of  moving  the  points  from  one  position  to 
the  other ;  then  there  is  a  second,  the  operation  of 
which  locks  them  or  unlocks  them,  as  the  need 
may  be. 

If  a  signalman,  then,  wishes  to  alter  the  facing 
points  at  a  junction,  he  has,  first  of  all,  to  unlock 
them  by  moving  one  lever,  then  he  sets  them  in  the 

168 


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RAILWAY  SIGNALS 

required  position  by  means  of  another  lever,  after 
which  he  locks  them  afresh  by  replacing  the  first  lever. 

The  locking  lever  does  its  work  through  a  small 
appliance  placed  upon  the  line  close  to  the  points, 
between  the  rails,  called  a  facing-point  lock.  It  is 
very  simple,  but  very  strong  and  reliable.  A  rod 
passes  from  each  tongue  of  the  points,  both  rods 
terminating  in  flat  portions  which  slide  in  a  groove 
in  the  apparatus.  Each  of  these  flat  pieces  has  a 
hole  in  it,  and  through  this  hole  there  can  shoot  a 
bolt  exactly  similar  to  the  bolt  with  which  we  fasten 
our  front  doors.  To  be  more  correct,  each  of  the 
flat  parts  has  two  holes,  so  placed  that  when  the 
points  are  correctly  set  in  one  position  the  bolt 
can  shoot  through  one  of  them,  and  when  in  the  other 
position  through  the  other. 

Consequently,  if  anything  should  go  wrong  with 
the  points,  so  that  they  do  not  close  properly,  the 
lock  will  not  operate,  for  the  bolt  will  not  pass  through 
either  of  the  holes.  Now  the  bolt  is  connected  by 
rods  to  the  locking  lever  in  the  signal  cabin,  so  that 
if  it  will  not  go  through  a  hole  the  signalman  finds 
himself  unable  to  work  his  lever  and  knows  that 
something  is  wrong.  More  than  that,  if  he  cannot 
work  his  lever  back  into  its  right  position,  his  signals 
are  locked.  Thus  we  see  that,  in  effect,  he  cannot 
possibly  lower  his  signals  for  a  train  to  approach 
the  junction  until  the  points  are  properly  set  and 
locked. 

It  is  interesting  to  notice,  too,  that  the  rod  from 
one  tongue  of  the  points  is  quite  separate  from 
that  from  the  other  tongue,  so  that  each  is  locked 

169 


RAILWAY  SIGNALS 

separately.  If  either  tongue  is  wrong,  therefore,  the 
signals  are  locked  at  danger. 

Indeed,  the  care  of  the  railway  authorities  goes 
even  farther  than  this,  for  in  many  such  cases 
"  detectors  "  are  employed  as  well.  It  is  just  possible 
that  a  long  run  of  rod  stretching  from  the  signal 
cabin  to  a  distant  junction  might  give  in  some  way, 
and  so  enable  a  signalman  to  move  his  lever  without 
actually  locking  the  points,  and  it  is  this  danger 
which  the  detector  guards  against. 

It  consists  of  a  small  cast-iron  box  securely  fixed 
to  the  sleepers  close  to  the  points  concerned.  Through 
it  there  pass  in  one  direction  two  slides,  connected 
to  the  two  tongues  of  the  points.  At  right  angles  to 
these  there  passes  another  slide.  The  single  slide 
crosses  over  the  other  two,  but  does  not  clear  it,  so 
a  notch  is  cut  in  it  through  which  the  edges  of  the 
two  slides  pass.  Thus,  you  see,  the  single  slide 
cannot  move,  because  of  the  two  slides  fitting  into 
the  notch. 

There  are,  however,  two  notches  in  each  of  the  two 
slides,  and  these  notches  are  made  to  correspond 
with  the  two  correct  positions  of  the  points.  When, 
therefore,  the  points  are  set  correctly  for  either 
route  the  single  slide  can  move,  but  if  the  points  or 
either  of  them  be  the  slightest  distance  out  of  a  correct 
position  the  single  slide  is  held. 

Now  the  wire  which  works  the  signal  protecting 
these  points  is  made  to  pass  through  the  single  slide, 
or  rather  the  wire  from  the  cabin  is  fastened  to  one 
end  of  it  and  the  wire  to  the  signal  is  attached  to 
the  other  end ;  in  other  words,  the  slide  forms  a 

170 


RAILWAY  SIGNALS 

part  of  the  connection  between  the  cabin  and  the 
signal,  so  that  if  the  points  be  wrong,  no  matter 
what  may  happen  in  the  signal  cabin,  the  signal 
itself  cannot  be  lowered.  Thus  every  possibility  of 
failure  is  provided  against. 

The  instrument  shelf  now  demands  our  attention. 
First  and  foremost,  the  "  block  telegraph  "  instru- 
ments call  for  notice.  If  would,  of  course,  be  quite 
possible  for  the  signalmen  to  communicate  to  each 
other  the  necessary  information  for  the  working  of 
the  trains  by  ordinary  telegraphy.  It  is  safer, 
however,  to  use  special  instruments.  There  are 
several  different  varieties  of  these,  but  in  essence 
they  are  the  same.  There  are,  of  course,  always  two, 
one  for  the  up  direction  and  one  for  the  down. 

Each  of  them  consists  of  a  neat  little  cabinet  with 
a  small  glazed  window,  while  at  some  convenient 
spot  there  is  placed  a  bell,  that  for  the  up  instrument 
being  markedly  different  in  tone  from  the  other. 

Normally,  there  shows  through  the  window  the 
words  "  line  blocked,"  while  the  operating  handle 
below  the  window  hangs  down  vertically. 

The  signalman  at  the  next  cabin,  by  means  of  a 
prearranged  number  of  rings  on  the  bell,  announces 
that  he  has  a  train  coming  along  and  asks  for  per- 
mission to  send  it  forward.  Our  signalman  moves 
the  little  handle  over  to  one  side  and  the  ticket  at 
the  window  changes  to  "  line  clear,"  the  instrument 
in  the  next  cabin  thereupon  doing  the  same.  The 
other  man  then  lowers  his  signals,  and  presently  a 
signal  on  the  bell  indicates  that  it  has  passed  him, 
whereupon  our  man  moves  his  handle  to  the  other 

171 


RAILWAY  SIGNALS 

side,  the  words  "  line  clear "  disappear  from  the 
window  and  "  train  on  line  "  takes  their  place. 

Presently,  when  the  train  has  passed,  our  man 
places  his  handle  vertically  again,  and  the  words 
"  line  blocked  "  reappear. 

This  apparatus  is  very  simple  and  therefore 
reliable.  Its  particular  virtue  is  that  it  sends  only 
three  messages,  the  vital  messages  for  maintaining 
the  safety  of  the  trains,  and  each  of  these  is  not  a 
momentary  signal,  but  remains  on  record  until  it 
is  cancelled  by  the  next  signal.  There  is  no  excuse 
for  a  man  thinking  he  has  received  the  "  line  clear  " 
signal  a  minute  ago  and  letting  a  train  pass  on  the 
strength  of  it.  Unless  the  words  are  actually  staring 
him  in  the  face  at  the  moment,  he  knows  that  he 
must  not  let  the  train  go. 

Another  thing  about  it,  and  this  aptly  illustrates 
what  has  been  described  as  the  third  great  principle 
of  railway  signalling,  is  that  any  failure  stops  the 
traffic  rather  than  endangers  the  trains.  The  normal 
signal  "  line  blocked  "  is  produced  by  the  cessation 
of  the  electric  current.  Battery  failure  or  the 
breakage  of  the  wire  would  not,  therefore,  bring  a 
train  into  danger. 

A  third  point  about  it,  simple,  yet  in  practice  very 
valuable,  is  that  both  instruments  act  in  unison,  so 
that  both  the  signalmen  know  what  signal  has  been 
sent  and  received,  thereby  making  for  a  complete 
understanding  between  the  two. 

Beside  these  instruments  there  are  a  number  of 
others  with  special  functions.  For  example,  signals 
which  cannot  be  seen  easily  from  the  cabin  are 

172 


RAILWAY  SIGNALS 

repeated  by  little  models.  There  is  a  neat  little  box 
with  a  glass  front,  and  inside  it  a  tiny  signal,  the  arm 
of  which  goes  up  and  down  in  unison  with  the  real 
signal  outside. 

The  acute  observer  may  have  noticed,  while 
waiting  at  a  station,  the  apparatus  upon  the  signal 
for  working  these  indicators.  It  consists  of  a  little 
round  box  fastened  actually  upon  the  signal  arm 
itself,  and  what  may  call  attention  to  it  is  that  a 
loop  of  flexible  wire  hangs  down,  connecting  this  to 
wires  upon  the  post.  Inside  this  little  box  there  are 
two  insulated  contacts  a  little  distance  apart,  and 
they  are  so  placed  that,  when  the  arm  is  horizontal, 
a  little  globule  of  mercury  falls  between  them  and 
makes  electrical  connection.  That  enables  current 
from  a  battery  to  flow  and  keeps  the  indicator  arm 
raised  also.  As  soon  as  the  signal  arm  is  lowered, 
however,  the  mercury  rolls  away  from  the  contacts, 
cuts  off  the  current  and  the  indicator  arm  goes 
down  also. 

Here  again  we  notice  two  things :  first,  that  by 
putting  the  apparatus  actually  on  the  signal  arm 
itself  several  possible  causes  of  failure  are  removed ; 
and  second,  that  failure  of  current  will  not  delude  the 
signalman  into  thinking  his  signal  is  at  danger  when, 
in  fact,  it  is  not. 

Other  indicators  show  whether  the  signal  lights 
are  burning  properly  or  not.  These  are  worked  by 
the  heat  of  the  lamp  expanding  a  metal  bar  and 
thereby  closing  two  contacts.  If  these  be  together, 
current  can  flow  from  a  battery  and  through  an 
indicator  in  the  cabin  which  shows  the  words  "  light 


RAILWAY  SIGNALS 

in."  If,  however,  the  lamp  should  go  out  or 
even  burn  badly  the  bar  will  cool,  the  contacts  will 
be  drawn  apart,  the  circuit  broken  and  the  indicator 
will  then  proclaim  "  light  out." 

In  addition  to  the  mechanical  and  electrical 
devices  for  making  railways  safe,  there  are  rules 
drawn  up  laying  down  certain  methods  which  must 
be  rigidly  adhered  to,  methods  which  may  be  said 
to  reinforce  the  purely  mechanical  or  electrical 
safeguards. 

The  devices  so  far  described  are  such  as  may  be 
found  in  the  great  majority  of  signal  cabins.  There 
are  many  others  of  a  more  or  less  special  nature,  in 
use  on  busy  lines  or  under  special  conditions.  For 
example,  there  are  places  where  the  signals  are 
worked  by  compressed  air  instead  of  by  hand,  others 
where  electricity  is  the  moving  force,  others  again 
where  points  are  worked  by  hand  and  signals  by 
electricity. 

There  are  stretches,  too,  where  the  rails  themselves 
are  made  to  do  the  signalling,  which  becomes  auto- 
matic. 

There  are  several  other  electrical  devices  which 
deserve  mention,  but  these  will  all  be  found  in  other 
chapters,  as  also  will  the  special  arrangements  for 
working  single  lines. 

This  chapter  is  intended  to  show  the  general 
basis  of  all  signalling,  without  which  the  later  descrip- 
tions might  be  hard  to  understand. 


CHAPTER  XIII 
AUTOMATIC  SIGNALLING 

ONE  of  the  most  fascinating  things  about  the 
modern  railway  is  the  way  in  which,  on  some 
lines,  the  trains  are  made  to  be  their  own  signal- 
men ;  or  rather,  to  put  it  more  accurately,  each  train 
acts  as  the  signalman  in  relation  to  the  next  one. 

As  a  typical  example  of  this  we  will  take  the 
arrangements  upon  the  Central  London  Railway, 
the  second,  in  point  of  time,  of  the  "  tube  "  railways  ; 
the  one,  in  fact,  in  connection  with  which  the  name 
"  tube  "  came  into  use.  The  previous  one,  the  City 
and  South  London,  was  never  called  a  tube,  but 
when  the  Central  London  was  first  opened  there  was 
a  universal  fare  of  twopence  for  any  distance,  and 
some  wag  hit  upon  the  idea  of  calling  it  the  "  two- 
penny tube  "  ;  the  name  "  caught  on,"  and  now  the 
word  tube  is  the  recognized  term  for  all  the  low-level 
underground  lines. 

Before  going  into  details,  however,  it  will  be  well 
to  explain  the  working  of  the  "  track  circuit,"  which 
is  the  basis  of  all  modern  automatic  signalling. 
There  are  one  or  two  examples  of  automatic  working 
controlled  by  other  means,  but  the  track  circuit 
is  so  simple  and  so  good  that  it  is  very  unlikely  that 


AUTOMATIC  SIGNALLING 

any  more  will  ever  be  installed,  except  those  based 
upon  it. 

The  track  circuit  as  an  invention  is  claimed  by 
both  Great  Britain  and  America.  Away  back  in  the 
'seventies  of  last  century  the  idea  occurred  to  William 
Robinson  of  Brooklyn  and  to  W.  R.  Sykes  of  London, 
and  in  all  probability  it  was  an  original  invention 
in  each  case,  neither  knowing  what  the  other  was 
doing.  This  simultaneous  invention  of  the  same 
thing  by  two  men  quite  independently  of  each  other 
is  not  at  all  an  uncommon  thing.  Another  feature 
in  which  the  track  circuit  resembles  many  other 
inventions  is  that  it  was  evidently  before  its  time, 
so  that  it  was  not  until  the  'nineties  that  it  came  to 
be  used  to  any  extent.  Now  it  is  used  more  or  less 
on  nearly  every  line. 

The  idea  in  itself  is  exceedingly  simple.  It  is 
based  upon  the  fact  that  wood,  even  when  wet,  is  a 
very  poor  conductor  of  electricity,  so  that  each  rail 
of  a  pair  is  fairly  well  insulated  from  the  other. 

Suppose,  then,  that  you  connect  a  small  battery, 
generating  a  force  of  a  few  volts,  between  the  two 
rails  of  a  pair  ;  very  little  current,  if  any,  will  flow. 
Then  a  train  comes  along  with  heavy  metal  wheels 
and  massive  axles  connecting  them.  These  wheels 
and  axles  form  a  path  for  the  current  from  rail  to 
rail  of  very  low  resistance  indeed,  with  the  result 
that  a  very  considerable  current  will  flow. 

Now  let  us  imagine  that  we  want  an  indicator 
which  will  warn  us  whenever  a  train  is  standing  or 
moving  in  a  certain  piece  of  line.  We  first  isolate 
that  piece  from  the  adjacent  line  by  means  of 

176 


0)      O 

JS    -(-> 


AUTOMATIC  SIGNALLING 

insulating  bonds.  These  are  specially  shaped  "fish- 
plates "  combined  with  insulating  material,  the  effect 
of  which  is  to  join  the  rails  firmly  to  the  adjacent 
rails  in  a  mechanical  sense,  yet  to  keep  them  quite 
separate  in  an  electrical  sense. 

Then  we  connect  our  battery  to  the  two  rails, 
placing  somewhere  in  the  wire  leading  from  the 
battery  to  one  rail  a  galvanometer,  or  other  instru- 


.  i  U*. 

=3S»  iPg  
t 

t 

I 

I 

1 

U    T. 

ffl 

,-    -  |,  | 

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Relay 


Relay 


Bettery 


Fig.  12. — DIAGRAM  SHOWING  HOW  A  TRACK  CIRCUIT 

WORKS  IN  ITS  SIMPLEST  FORM. 
(Worked  by  steady  current  from  a  battery.) 

I,  I,  I,  are  insulating  joints  in  the  rails.  Arrows  show  course 
of  current.  In  the  right-hand  section  the  current  has  to  pass 
through  and  energize  the  relay.  In  the  left-hand  section  the 
pair  of  wheels  form  an  easier  path  for  the  current,  which  is 
thereby  cut  off  from  the  relay.  The  relay  controls  the  signal 
or  other  apparatus.  (Alternating  current  track  circuits  are 
just  the  same  in  principle.) 

ment  which  tells  us  when  current  is  flowing.  If  we 
watch  the  galvanometer  as  a  train  approaches  this 
insulated  "  section  "  of  line  we  shall  see  the  needle 
suddenly  swing  over,  indicating  that  the  train  has 
entered  the  section.  Later  we  shall  see  it  swing 
back,  and  then  we  shall  know  that  it  has  passed  out 
at  the  other  end  of  the  section.  But  so  long  as  the 
section  is  occupied  the  needle  will  be  held  over  by  the 
current. 

M  177 


AUTOMATIC  SIGNALLING 

That  would  be  a  form  of  track  circuit,  but  it  would 
suffer  from  a  very  serious  fault  so  far  as  signalling 
is  concerned.  The  fault  is  this  :  the  breakage  of 
one  of  the  wires,  or  the  failure  of  the  battery  would 
give  the  same  indication  as  the  absence  of  a  train. 
Consequently,  a  train  might  be  in  the  section  while, 
owing  to  one  of  these  quite  possible  accidents,  the 
galvanometer  would  show  the  section  clear. 

Fortunately  that  difficulty  can  be  overcome  quite 
easily.  Let  us  connect  the  battery  to  the  two  rails 
at  one  end  of  the  section  and  the  galvanometer  to  the 
same  rails  at  some  other  point.  The  current  will 
then  flow  along  one  rail,  through  the  galvanometer 
and  back  along  the  other  rail,  and  so  long  as  the 
section  is  clear  the  galvanometer  needle  will  be  held 
over.  As  soon  as  a  train  enters  the  section,  however, 
the  wheels  and  axles  will  afford  the  current  a  much 
easier  path  than  that  through  the  galvanometer, 
with  the  result  that  nearly  all  of  it  will  take  that 
path  and  very  little  indeed  will  pass  through  the 
galvanometer,  the  needle  of  which  will  go  to  zero. 

Under  this  arrangement  the  breakage  of  a  wire 
or  the  failure  of  a  battery  will  give  the  same  indica- 
tion as  the  presence  of  a  train  in  the  section,  so  that 
an  error,  if  it  occurs,  makes  for  safety. 

The  principle  of  the  track  circuit,  therefore,  as 
used,  is  that  the  train  itself  forms  an  easy  path  for 
the  current  and  thereby  short  circuits  it,  or  in  other 
words,  leads  it  away  from  the  indicating  instrument. 
The  latter  is  normally  energized  by  the  current 
from  the  battery,  and  the  train  indicates  its  presence 
by  depriving  it  of  the  current. 

178 


AUTOMATIC  SIGNALLING 

In  practice  very  feeble  currents  are  employed  for 
this  work,  far  too  feeble  to  work  a  signal,  or,  indeed, 
anything  heavier  than  a  very  delicate  instrument, 
hence  the  use  of  what  is  called  a  "  relay."  These 
are  instruments  which  are  in  themselves  quite 
robust,  but  which  contain  one  very  light  moving 
part  very  delicately  poised.  This  the  feeble  currents 
are  able  to  move,  and  by  moving  complete  or  break 
a  second  circuit  through  which  can  flow  a  powerful 
current  from  a  local  source.  Thus  the  feeble  current 
from  the  track  circuit  can  be  made  to  control  a 
second  current  of  any  power  required,  to  work 
signals  or  other  apparatus. 

On  steam  lines  the  use  of  track  circuits  is  a  very 
simple  matter,  because  the  lines  can  be  divided  up 
into  sections,  and  the  sections  insulated  from  each 
other  without  difficulty.  On  electrically  driven 
lines,  however,  the  rails  often  form  the  return  path 
for  the  traction  current,  so  that  they  cannot  be 
completely  insulated  from  each  other  ;  or  even  if 
there  be  a  fourth  rail  for  the  return  of  the  traction 
current  some  of  the  latter  might  by  accident  leak 
on  to  one  of  the  track  rails  and  interfere  with  the 
track  circuits.  The  Central  London  will  provide  us 
with  an  example  of  how  this  problem  is  simply  and 
satisfactorily  dealt  with. 

When  it  was  first  built  it  was  signalled  on  the 
system  known  as  "  lock  and  block."  Under  this, 
the  line  is  divided  up  into  "  sections,"  and  not  more 
than  one  train  is  allowed  to  be  in  a  section  at  one 
time. 

To  ensure  this  there  is  a  signal  box  at  the 

179 


AUTOMATIC  SIGNALLING 

commencement  of  each  section  and  a  signal.  All 
the  boxes  are  connected  by  telegraph  wires  and  fitted 
with  certain  special  instruments.  Let  us  take  two 
boxes,  by  way  of  illustration,  and  call  them  A 
andB. 

A  train  is  approaching  A,  and  the  signalman,  let 
us  suppose,  tries  to  lower  his  signal  to  let  it  pass. 
He  finds  that  he  cannot  do  so,  for  it  is  locked.  He, 
therefore,  sends  a  message  by  wire  to  B  box  asking 
the  man  there  for  permission  to  send  the  train  on. 
If  all  is  clear,  B  sends  back  a  message  over  the  wires 
in  a  certain  prearranged  way  which  has  the  effect  of 
unlocking  the  lever  at  A  box.  The  A  man  then 
lowers  his  signal  and  allows  the  train  to  proceed. 

Suppose  now  that  a  second  train  quickly  approaches 
A,  and  A  again  asks  B  for  permission  to  send  it 
forward.  B  cannot  now  send  back  the  required 
message  because,  after  sending  it  for  the  previous 
train,  his  instrument  became  locked  until  such  time 
as  the  first  train  should  pass  over  a  treadle  under 
the  rail,  and  by  so  doing  release  it.  Thus  the  second 
train  has  to  wait  at  A  until  the  first  train  has  passed 
out  of  the  section,  and  in  doing  so  has  unlocked  the 
instrument  at  B.  Then,  and  only  then,  can  the  man 
at  B  send  the  series  of  electrical  currents  necessary 
to  unlock  A  lever  again.  As  a  matter  of  fact,  the 
careful  signalman  would  not  attempt  to  make  these 
movements,  but  it  has  been  put  like  that  in  order 
to  show  that  if  by  accident  he  should  attempt  to 
do  so  he  would  be  prevented  by  the  apparatus. 

Now  it  will  be  realized  readily  that  to  go  through 
this  series  of  operations — the  exchanging  of  the 

180 


AUTOMATIC  SIGNALLING 

necessary  messages  with  the  next  box  and  the  pulling 
of  the  necessary  levers — takes  an  appreciable  time. 

It  will  also  be  readily  understood  that  the  number 
of  trains  which  a  line  can  accommodate  will  depend 
upon  the  length  of  the  sections.  By  reducing  the 
length  of  the  sections  the  trains  can  be  brought 
closer  together  and  more  of  them  got  through  in  a 
given  time.  But  clearly,  it  is  no  use  to  make  a 
section  so  short  that  a  train  can  pass  from  end  to 
end  in  less  time  than  the  signalling  takes  up.  Such 
a  section  would  be  a  cause  of  delay  rather  than 
the  reverse,  because  trains  would  always  be  stopped 
while  the  signalling  operations  were  carried  through. 

This  was  the  dilemma  which  faced  the  directors 
of  the  Central  London.  They  wanted  to  increase 
the  density  of  the  traffic,  in  other  words,  to  run  the 
trains  closer  together,  yet  the  signalling  system  then 
in  vogue  prevented  it.  Hence  they  were  compelled 
to  adopt  the  automatic  system  which  was  already 
doing  so  well  on  other  underground  lines  in  London. 

The  first  thing  to  be  done  was  to  divide  up  the  line 
by  insulating  joints  into  suitable  sections,  electrically 
insulated  from  each  other,  so  that  track  circuits 
could  be  installed.  But,  as  already  pointed  out,  the 
rails  are  required  to  carry  the  return  traction  current. 
It  was  therefore  necessary  to  insert  a  device  at  each 
joint  whereby  the  traction  current  could  "  dodge 
round  "  the  insulating  bond,  while  the  track  circuit 
current  would  be  stopped.  At  first  sight  this  seems 
impossible,  but  it  is  quite  simple  if  you  employ  two 
different  kinds  of  current. 

As  explained  in  the  chapter  on  electric  traction, 

181 


AUTOMATIC  SIGNALLING 

there  are  two  sorts  of  electric  currents.  The  elec- 
tricity is  just  the  same  ;  it  is  only  the  current  which 
varies.  One  of  these  flows  straight  on,  always  in 
the  same  direction.  The  other  "  alternates,"  flowing 
first  in  one  direction,  then  in  the  other,  generally, 
in  practice,  making  a  complete  set  of  changes  fifty 
times  every  second.  The  first  sort  of  current,  con- 
tinuous or  direct,  flows  through  any  coil  of  wire 


Rail  Rail 


ARROWS    SHOW     COURSE    OF 
TRACTION     CURRENT 


J          Rail  ||  Rail ^ 

Fig.  13. — DIAGRAM  SHOWING  HOW  THE  IMPEDANCE  BOND 

IS    ARRANGED. 

It  sorts  out  the  two  kinds  of  current,  allowing  the  traction 
current  to  pass  but  stopping  the  signal  current. 

I,  I,  Insulating  joints.  The  impedance  bonds  consists  of  iron 
cores,  wound,  as  shown,  with  thick  copper  wire.  Coils  so 
formed  pass  steady  current  with  ease,  but  offer  an  almost 
insuperable  obstacle  to  alternating  current. 

quite  readily.  If,  however,  the  coil  be  mounted 
upon  an  iron  core,  it  acquires  a  property  called 
"  Impedance,"  which  offers  considerable  obstruction 
to  the  passage  of  an  alternating  current. 

At  every  insulated  joint,  therefore,  an  "  im- 
pedance bond "  has  been  placed,  through  which 
the  direct  or  continuous  current  from  the  motors 
flows  past  the  insulation,  while  the  alternating 
current  for  the  track  circuit  operations  is  stopped. 

182 


AUTOMATIC  SIGNALLING 

The  "  impedance  bond "  is  quite  simple  in  con- 
struction, being  merely  a  bar  of  copper  bent  round 
into  a  coil,  with  a  suitable  iron  core  inside  it,  the 
whole  contained  in  an  iron  box  fixed  to  the  sleepers. 
It  is  connected  to  the  rails  by  flexible  cables.  It 
needs  little  or  no  attention,  but  may  safely  be  left 
to  do  its  duty. 

But,  someone  may  ask,  is  it  not  possible  for  the 
traction  current  to  get  to  the  relay  instead  of  the 
track  circuit  current,  and  so  give  a  false  signal  ?  It 
may  get  there,  but  it  cannot  give  a  false  signal. 
Just  as  the  impedance  coil  can  discriminate  between 
alternating  and  direct  current,  so  can  relays.  In 
this  case  a  type  of  relay  is  used  which  will  respond 
to  an  alternating  current,  but  will  take  absolutely 
no  notice  of  a  direct  current. 

We  are,  however,  getting  on  too  fast.  The  line, 
we  will  take  it,  has  been  divided  up  into  convenient 
sections,  the  divisions  being  in  many  cases  the  same 
as  before,  but  in  other  cases  altered  in  order  to  reduce 
the  length  of  some  of  the  sections  and  so  expedite 
the  traffic.  Except  in  a  few  cases  the  signal  boxes 
disappear  entirely,  as  signal  boxes  at  all  events. 
Instead  of  the  levers  in  the  signal  boxes  the  track 
circuits  take  control  of  the  signals,  in  the  following 
simple  manner.  By  entering  a  section,  a  train  short 
circuits  a  relay  as  already  explained,  and  that  puts 
to  danger  a  signal  behind  it.  So  long  as  the  train 
remains  in  the  section  that  signal  remains  at  danger, 
but  when  it  passes  out  of  the  section  the  signal  goes 
to  "  clear." 

Unlike  the  ordinary  line,  where  the  signals  are 

183 


AUTOMATIC  SIGNALLING 

normally  at  danger,  these  signals  are  normally  at 
"  clear,"  but  each  train  as  it  goes  puts  the  signal 
immediately  behind  it  to  danger,  thereby  preventing 
the  next  train  from  following  too  closely.  The 
second  train,  it  will  be  noticed,  can  never  enter  a 
section  until  the  previous  one  has  left  it.  Two  trains 
can  never  be  in  a  section  together. 

To  make  assurance  doubly  sure,  there  is  on  the 
ground  near  each  signal  an  "  automatic  stop."  This 
is  a  mechanical  device  which  works  in  conjunction 
with  the  signal.  When  the  signal  goes  to  danger  an 
iron  arm  rises  up  and  stands  in  the  way  of  a  pro- 
jecting lever  upon  the  trains.  This  lever  is  in  effect 
the  handle  of  a  cock,  the  opening  of  which  puts  on 
the  compressed  air  brake  upon  the  train.  Should  a 
train,  therefore,  overrun  a  signal  this  comes  into 
operation,  the  brake  goes  on  and  the  train  is  quickly 
brought  to  a  standstill.  When  the  signal  is  at "  clear," 
however,  the  arm  lies  down  out  of  the  way  of  the 
lever  on  the  train,  so  that  the  trains  can  run  past  it. 

As  a  matter  of  fact,  the  insulating  joints  which 
form  the  ends  of  the  track  circuits  are  not  just 
where  the  signals  are,  but  are  some  distance  farther 
on.  This  distance,  which  is  called  the  "  overlap," 
varies  according  to  the  gradient  of  the  line  at  the 
point,  the  idea  being  that  it  shall  be  long  enough  for 
a  train  to  pull  up  in.  But  for  this  arrangement  a 
train  might  stop  just  beyond  a  signal,  and  a  second 
train  coming  upon  that  signal  unexpectedly  might 
be  unable  to  pull  up  in  time  and  so  run  into  the  one 
in  front.  With  the  overlap,  however,  this  can  never 
happen. 

184 


AUTOMATIC  SIGNALLING 


The  signals  on  this  line  are  not  movable,  but 
consist  of  two  electric  lights,  one  above  the  other,  one 
with  a  red  lens  and  one  with  a  green  lens  ;  only  one 


Two  Coils  of  wire 
hown  separate  but 
actually  wound   on 
same  Iron  core 


Supply  Mains.  -< 


Fig.  14. — DIAGRAM  SHOWING  HOW  ONE  RELAY  CONTROLS 

BOTH   THE   RED   AND    THE   GREEN   LAMP. 

When  the  relay  is  caused  by  the  track  circuit  to  open,  current 
flows  from  the  main  at  A  through  the  red  lamp.  When  the 
relay  closes,  current  flows  from  the  main  through  the  green 
lamp.  It  also  neutralizes  the  impedance  in  the  coil  so  that  the 
red  lamp  becomes  short-circuited. 

is  illuminated  at  a  time.  When  the  line  is  clear  the 
green  one  lights  up,  when  it  is  otherwise  the  red  one 
shows. 

185 


AUTOMATIC  SIGNALLING 

At  first  sight  it  seems  as  if  this  might  be  dangerous, 
for  we  all  know  what  tricks  electric  wires  play  at 
times,  and  it  seems  possible  that  through  a  short 
circuit  the  green  might  show  when  it  ought  to  be  red. 
This  possibility  is  provided  against  in  a  very  ingenious 
manner. 

The  current  from  the  supply  passes  through  the 
relay  to  the  green  light  and  then  through  a  small 
coil.  Current  also  passes  from  the  supply  to  the  red 
light,  but  the  line  to  the  red  light  forks,  the  light 
being  in  one  branch  and  another  small  coil  in  the 
other  branch.  The  current  to  the  red  light  circuit 
is  always  on. 

Let  us  assume  that  there  is  a  train  in  the  section, 
in  which  case  the  relay  is  open  and  no  current  is 
flowing  to  the  green  light.  The  current  in  the  red 
light  circuit  has  two  paths  open  to  it,  one  through 
the  light  and  the  other  through  the  coil.  But,  as 
we  saw  just  now,  a  coil  has  the  property  called 
"  impedance,"  which  obstructs  the  passage  of  alter- 
nating current,  which  this  current  is.  Therefore,  the 
path  through  the  coil  is  almost  blocked  and  practically 
the  whole  of  the  current  passes  through  the  light, 
which  glows  brightly. 

But  now  let  us  suppose  that  the  train  has  passed 
out  of  the  section.  The  relay  closes  the  green  circuit 
and  the  green  light  shows.  Of  course,  when  the 
current  flows  to  the  green  light  it  also  flows  through 
the  small  coil  which  is  in  the  same  circuit,  and  that 
small  coil  is  wound  with  the  other  small  coil  around 
the  same  core.  The  effect  of  the  green  coil  upon 
the  red  coil  is  to  reduce  the  impedance  of  the  latter, 

1 86 


AUTOMATIC  SIGNALLING 

with  the  result  that  current  flows  freely  through  it 
and  scarcely  any  through  the  red  light,  which  there- 
upon goes  out.  Thus  the  one  relay  controls  both 
circuits,  and  whatever  happens  a  dangerous  indica- 
tion cannot  be  given.  The  two  lights  may  under 
certain  conditions  light  up  together,  but  under  no 
conditions  can  the  green  light  show  alone  when  it 
ought  to  be  red.  The  failure  of  an  electric  light  bulb 
is  provided  against  by  having  two  for  each  colour  of 
different  ages. 

Most  of  the  signals  are,  of  course,  in  tunnels,  but 
those  which  are  in  the  open  are  (with  one  exception) 
of  the  same  type,  a  hood  being  placed  over  each  so 
that  it  can  be  seen  clearly  from  a  distance  even  in 
broad  daylight. 

There  are  no  distant  signals  on  this  line,  but  in 
many  cases,  where  an  approaching  driver  does  not 
get  an  uninterrupted  view  of  the  signals,  repeater 
signals  are  used.  These  are  just  the  same,  except  that 
instead  of  being  red  and  green  they  are  yellow  and  green. 

At  one  or  two  spots  on  the  line  there  are  cross- 
overs or  sidings,  and  at  such  points  the  old  locking- 
frame  remains.  These  locking-frames  are,  however, 
worked  into  the  automatic  system  in  a  beautifully 
simple  manner. 

The  levers  are  still  there  and  the  rods  for  operating 
the  points,  but  the  old  signal  has  gone,  its  place 
having  been  taken  by  an  automatic  signal.  The 
lever  which  used  to  work  it  has  been  fitted  with  an 
electric  switch,  through  which  passes  the  current 
from  the  track  circuit.  When  this  lever  is  pulled 
the  switch  is  closed  and  the  signal  is  then  controlled 

187 


AUTOMATIC  SIGNALLING 

solely  by  the  track  circuit.  When  it  is  put  back  the 
switch  is  thereby  opened  and  the  signal  goes  to 
danger  just  as  if  it  had  been  operated  by  a  train. 

Normally,  then,  the  lever  is  left  in  the  "  pulled  " 
position,  under  which  conditions  the  signal  works 
automatically,  as  if  the  lever  did  not  exist,  and  the 
point  levers  are  securely  locked.  When  it  is  put  back, 
however,  it  sets  the  signal  to  danger  and  also, 
through  the  working  of  the  ordinary  inter-locking 
mechanism,  frees  the  point  levers.  During  the 
shunting  the  point  levers  themselves,  as  of  old,  lock 
the  signal  lever  and  so  keep  the  signal  at  danger, 
but  when  the  shunt  is  completed  and  the  points 
have  been  restored  the  signal  lever  can  be  pulled  once 
more  and  the  automatic  working  is  thereby  restored. 

At  the  two  ends  of  the  line  there  are  small  signal 
boxes  fitted  up  on  the  electro-pneumatic  principle. 

There  is  a  supply  of  alternating  current  all  along 
the  line  for  lighting  and  the  current  for  the  track 
circuits  is  drawn  from  the  same  source,  the  correct 
voltage  being  obtained  by  means  of  transformers, 
small  "  induction  coils  "  by  which  the  voltage  of 
alternating  current  can  be  easily  changed. 

The  points  at  the  two  terminal  stations  and  the 
train-stops  are  actuated  by  compressed  air  at  60  Ibs. 
pressure  carried  in  small  iron  pipes. 

More  recently  a  line  has  been  constructed  forming 
a  continuation  of  the  Central  London  line  as  far  as 
Baling,  and  this  provides  us  with  further  interesting 
examples  of  signalling,  inasmuch  as  parts  of  it  are 
"  semi-automatic,"  and  there  is  in  use  what  is  known 
as  the  "  three-position  upper-quadrant  "  signal. 

188 


AUTOMATIC  SIGNALLING 

Semi-automatic  signalling  differs  from  automatic 
in  that  the  signals  are  to  some  extent  worked  by  a 
signalman  from  a  signal  box,  but  his  actions  are 
subject  to  restraint  by  track  circuits,  and  under  certain 
conditions  the  signals  go  to  danger  automatically. 

The  term  "  upper  quadrant "  means  that  the 
signal  arm,  instead  of  moving  downwards  through 
the  "  lower  quadrant  "  to  indicate  "  clear,"  rises  into 
the  "  upper  quadrant."  In  three-position  signals 
the  arm  rises  from  the  horizontal,  which  as  usual 

(8)1      I  (b)l      i (c)|      I (d)l       I     _ 

(1)  J          (2)  (3)  '  (4)  J/?) 

I  I  I  I 

Fig.  15. — DIAGRAM  SHOWING  THE  OPERATION  or  THREE- 
POSITION  SIGNALS  WORKED  AUTOMATICALLY. 

I = Insulating  joints  in  rails.  Direction  of  traffic — left  to  right. 
One  train  (denoted  by  the  pair  of  wheels  on  right-hand  side) 
has  just  passed  into  section  (5),  consequently  signal  (d)  is  at 
danger,  signal  (c)  is  at  caution  and  signal  (b)  is  at  clear. 

The  second  train,  having  just  passed  from  section  (1)  into 
section  (2),  has  itself  put  signal  (a)  to  danger.  Signal  (b)  is 
now  clear,  but  will  change  to  danger  as  soon  as  the  train  enters 
section  (3).  At  that  moment,  too,  signal  (a)  will  go  to  caution. 

means  "  stop,"  to  a  mid  position,  which  means 
"  proceed  with  caution,"  or  to  a  vertical  position, 
which  indicates  "  clear." 

The  use  of  the  upper  quadrant  is  convenient  in 
that  it  removes  the  necessity  of  balancing  the  arm 
in  order  to  make  it  go  to  danger  of  itself.  It  also 
has  the  result  that  something  falling  upon  it,  such 
as  snow,  cannot  make  it  take  up  the  "  clear  "  position 
when  it  ought  not  to  do  so.  Further,  when  the  three- 
positions  are  used,  the  upper  quadrant  is  almost 
essential,  because  the  interference  of  the  post  makes 

189 


AUTOMATIC  SIGNALLING 

it    practically    impossible    to    obtain    three    clearly 
discernible  positions  in  the  lower  quadrant. 

A  three-position  signal  in  the  "  caution  "  position 
shows  a  yellow  light,  the  lights  for  the  other  positions 
being  red  and  green  as  usual. 

The  signals  in  this  case  are  not  only  controlled, 
but  actually  moved  by  electricity,  there  being  a 
little  motor  on  the  post  for  that  purpose. 

Taking  those  parts  of  the  line  where  the  working 
is  automatic  the  three-position  signals  work  in  the 
following  manner. 

A  signal  is  at  danger,  a  train  having  just  entered 
the  section.  As  soon  as  it  leaves  the  section  the 
arm  goes  up  half-way.  When  it  leaves  the  next 
section  it  goes  right  up.  The  movements  of  the 
signal,  therefore,  are  controlled  by  the  mutual 
action  of  two  track  circuits,  the  first  of  which  can 
put  the  arm  to  the  caution  position,  but  both  of 
which  are  necessary  to  put  it  to  the  clear  position. 

In  all  cases  the  action  of  the  signal  arm  is  pro- 
duced by  current  flowing  from  a  relay  to  the  motor 
and  causing  it  to  wind  up  the  signal  arm,  so  to  speak, 
to  the  required  position,  where  it  is  held  by  a  magnet. 
Any  interruption  of  the  current  de-energizes  the 
magnet  and  permits  the  arm  to  fall  back  to  danger. 

The  semi-automatic  working  is  at  junctions  where 
the  intervention  of  a  human  intelligence  is  absolutely 
necessary.  What  it  amounts  to  is  that  the  signalman 
can  put  to  danger  signals  which  the  track  circuits 
would  leave  at  "  clear,"  in  order  to  manipulate 
points.  The  track  circuits,  however,  remain  on 
guard,  as  it  were,  preventing  the  man  from  putting 
signals  to  "  clear  "  when  it  is  not  safe  to  do  so. 

190 


AUTOMATIC  SIGNALLING 

Signals  which  are  automatic  are,  on  this  line, 
distinguished  from  those  which  are  under  human 
supervision  by  having  pointed  ends  instead  of  the 
usual  square  ends.  The  reason  for  this  is  interesting. 
If  an  ordinary  signal  goes  out  of  order  and  stops  a 
train  when  it  need  not  do  so,  the  signalman  can  take 
steps  to  remedy  the  defect  at  once,  or  can  signal  the 
train  forward  by  hand.  If,  however,  an  automatic 
signal  did  the  same  thing  it  might  be  that  no  one  in 
the  signal  department  knew  about  it  for  some  con- 
siderable time,  during  which  a  train  might  be  standing 
needlessly  at  it.  The  rule  is,  therefore,  that  after  a 
train  has  come  to  a  standstill  and  stood  still  for  one 
minute  it  may  move  on  past  an  automatic  signal, 
but  it  must  move  cautiously,  being  prepared  to  stop 
short  of  any  obstruction  which  it  might  find  ahead. 

On  some  lines,  it  may  be  remarked  here,  the 
automatic  signals  are  indicated  by  a  black  line 
running  lengthwise  of  the  arm. 

Where  signal  levers  are  used  it  is  so  arranged  that 
the  signalman  can  at  first  only  move  his  lever  a 
part  of  the  way.  This  sets  going  the  signalling  or 
point-moving  operation  which  he  desires,  and  when 
that  is  complete  a  return  indication  frees  his  lever, 
so  that  he  can  complete  the  movement.  It  is  this 
last  little  part  of  the  movement  which  operates  the 
interlocking  mechanism,  so  that  other  levers  are  not 
unlocked  until  not  only  has  the  first  lever  been 
moved,  but  the  distant  apparatus  has  actually  re- 
sponded to  the  movement. 

It  is  difficult  to  see  how  any  safety  device  could  be 
more  complete. 

191 


CHAPTER  XIV 

THE  SIGNALLING  OF  A  LARGE 
TERMINUS 

IN  a  previous  chapter  there  has  been  described 
the  simple  general  principles  of  signalling,  and 
what  has  been  said  there  will  enable  anyone  to 
understand  the  operation  of  the  signals  which  afford 
so  much  interest  during  a  wait  at  a  small  wayside 
station.  This  chapter  deals  with  a  very  up-to-date 
system  of  power  signalling  at  the  Central  Station, 
Glasgow,  in  its  way  one  of  the  wonders  of  the  world. 

The  term  "  power  signalling "  means  that  the 
points  and  signals  are  not  moved  by  the  muscles  of 
the  signalman,  but  by  some  form  of  power,  the 
signalman  only  opening  or  closing  certain  cocks  or 
switches  which  control  the  power. 

In  this  particular  case  the  power  is  electro-pneu- 
matic, the  actual  movements  being  made  by  com- 
pressed air,  the  valves  of  the  compressed-air  motors 
being  operated  by  electric  currents,  which  in  turn 
are  controlled  by  switches  in  the  signal  cabin. 

In  every  signal  cabin  the  levers  are  placed  in  a 
long  row,  mounted  in  framing  which  forms  guides 
and  supports  for  them,  while  close  by,  usually  beneath, 
is  the  interlocking  apparatus,  the  whole  thing  being 

192 


SIGNALLING  OF  A  LARGE  TERMINUS 

called  an  "  interlocking  frame."  The  same  general 
form  is  retained  even  when  the  long  levers  of  the 
hand-worked  apparatus  give  place  to  the  small 
switches  of  the  electro-pneumatic.  Thus,  in  this 
great  cabin,  we  have  a  frame  of  374  levers,  all  mounted 
in  one  row,  with  the  interlocking  apparatus  just 
beneath.  The  levers,  while  in  general  form  similar 
to  the  large  ones,  are  quite  small  and  the  power 
required  to  move  them  is  very  little.  Thus,  a  man 
can  look  after  a  much  larger  number  of  levers  than 
he  could  do  if  he  had  to  work  them  by  his  own 
power,  and  the  staff  of  men  required  is  thereby 
reduced. 

Further,  it  is  possible  when  using  power  to  work 
points  situated  much  farther  from  the  cabin  than  is 
practicable  with  human  muscles  with  the  result  that, 
as  in  this  case,  the  whole  working  of  a  vast  station 
can  be  controlled  from  one  cabin. 

There  is  yet  another  point  which,  in  a  case  like  this, 
is  very  important.  The  number  of  lines  with  the 
necessary  points,  crossings  and  signals  is  so  great 
that  the  rods  and  wires  necessary  to  work  them  by 
hand  would  monopolize  room  on  the  ground  which 
cannot  be  spared.  The  pipes  and  electric  wires 
needed  for  the  electro-pneumatic  scheme  can  be 
bunched  together  and  stowed  away  in  places  which 
would  be  quite  impossible  with  rods  and  wires  that 
had  to  be  movable. 

The  particular  system  used  here  is  the  Westing- 
house,  a  system  which  originated  in  the  United 
States,  but  which  has  been  adopted  in  Great  Britain, 
although  to  some  extent  modified  in  order  to  adapt 

N  I93 


SIGNALLING  OF  A  LARGE  TERMINUS 

it  more  effectively  to  the  conditions  which  prevail 
here. 

Each  little  lever  is  interlocked  with  its  fellows  in  a 
manner  very  similar  to  that  described  previously  and 
the  motion  of  a  lever  makes  or  breaks  certain 
electrical  contacts,  sending  or  stopping  currents 
which  flow  to  the  various  "  motors,"  upon  the  signals 
or  on  the  ground  near  the  points. 

The  motors  are  cylinders  of  cast  iron  with  a  piston 
inside  each,  and  a  piston  rod  very  like  that  of  a 
steam  engine.  Pipes  run  to  all  the  motors  carrying 
compressed  air  at  a  pressure  of  about  70  Ibs.  per 
square  inch. 

The  valves  which  permit  the  compressed  air  to 
enter  the  motors  are  worked  by  an  electro-magnet, 
which  is  energized  by  the  current  from  the  cabin  ; 
so  that  a  current  on  flowing  gives  strength  to  the 
magnet,  thereby  opening  the  valve  and  permitting 
the  compressed  air  to  move  the  piston,  the  rod  of 
which  communicates  its  movement  to  the  points  or 
other  mechanism. 

The  signal  cabin  which  we  are  now  considering  is 
a  two-story  structure  about  107  ft.  long  and  16  ft. 
wide.  The  upper  floor,  the  signal  box  proper,  has 
glass  windows  practically  all  round,  so  that  the 
signalmen  have  an  uninterrupted  view  in  all  directions, 
and  in  addition  there  are  four  projecting  bay  windows 
from  which  the  men  can  get  a  better  view  lengthwise 
of  the  cabin.  It  is  on  this  upper  floor,  of  course, 
that  the  frame  is  placed. 

All  the  signal  posts  in  this  installation  are  iron, 
and  many  of  them  are  arranged  upon  bridges  which 

194 


SIGNALLING  OF  A  LARGE  TERMINUS 

span  the  line  from  side  to  side.  There  are  fifteen  of 
these  bridges,  one,  at  least,  of  which  is  well  over 
100  ft.  long. 

There  are,  to  the  observer,  strangely  few  signals 
for  so  busy  a  station,  the  reason  being  a  very  in- 
teresting one. 

Suppose  that  from  one  line  it  is  possible  to  enter 
three  platforms.  There  would  be,  under  the  ordinary 
arrangement,  three  signals.  In  this  case  there  is 
only  one,  but  in  addition  to  that  one  there  is  an 
indicator  showing  the  words  "  To  Platform  "  and  a 
large  number.  Thus,  whatever  platform  the  train 
may  be  intended  to  enter  is  indicated  by  the  number, 
and  the  one  signal  arm  suffices  for  all  three. 

The  great  advantage  of  this  arrangement  is  that 
by  reducing  the  number  of  arms  very  considerably 
it  simplifies  the  work  of  the  drivers.  Instead  of 
having  to  pick  one  arm  out  of  a  number  and  to 
count  upwards  or  downwards  to  see  which  platform 
it  relates  to,  he  has  only  the  one  arm  and  the  in- 
dicator, which  he  reads  instantly  and  without  effort. 

The  same  principle  is  applied  for  trains  coming 
out  of  the  station.  In  that  case  there  are  several 
ways  from  each  platform  on  to  different  roads,  so 
that  for  each  platform  there  is  one  signal  and  below 
it  an  indicator  with  the  words  "  To  Line  "  and  a 
number. 

The  indicators  consist  of  a  case  with  slides  in  it, 
each  slide  having  a  different  number  upon  it.  The 
slides  normally  reside  in  the  upper  part  of  the  case, 
behind  the  words  "  To  Platform,"  or  "  To  Line,"  as 
the  case  may  be.  The  case  also  contains  a  shutter, 

195 


SIGNALLING  OF  A  LARGE  TERMINUS 

which  is  normally  down  and  remains  down  so  long 
as  the  signal  is  at  "  danger." 

It  must  not  be  thought  that  there  is  only  one  lever 
because  there  is  only  one  arm.  There  are,  in  fact, 
the  same  number  of  levers  as  there  would  be  arms 
under  the  ordinary  conditions.  On  one  of  these 
being  pulled,  it  sends  a  current  to  the  signal  which 
operates  an  electric  lock  and  so  releases  one  of  the 
slides.  This  current  also  starts  a  motor,  which  lowers 
the  correct  slide  into  position  behind  the  shutter. 
When  the  slide  has  descended  to  its  correct  position 
it  closes  an  electric  contact,  which  sets  another 
motor  going  and  this  motor  lowers  the  signal  arm 
and  raises  the  shutter. 

It  often  happens  in  a  terminus  such  as  this  that  a 
train  is  at  a  platform  where  it  is  desired  to  put  a 
second  train.  If,  under  such  conditions,  the  ordinary 
signal  were  used  the  driver  would  probably  think 
that  the  platform  was  clear  and  he  would  go  in 
prepared  to  stop  at  the  farther  end,  with  the  result 
that  he  would  be  quite  likely  to  crash  into  the  train 
already  there.  To  meet  this  difficulty  there  is,  under 
the  other  arm,  a  smaller  one  called  a  "  calling-on  " 
arm,  the  purpose  of  which  is  to  tell  the  man  to  move 
forward,  but  to  go  slowly  and  carefully  so  that  he 
can  stop  short  of  any  obstruction  which  he  may 
encounter.  This  arm  is  worked  in  just  the  same  way 
as  the  other,  but  by  a  separate  lever. 

At  several  points  in  the  area  controlled  from  the 
signal  box  there  are  points  for  shunting  which  it  is 
not  convenient  to  work  from  the  box  itself.  These 
are,  therefore,  worked  by  the  shunters  themselves 

196 


SIGNALLING  OF  A  LARGE  TERMINUS 

by  means  of  "  ground-frames,"  by  which  is  meant 
levers  mounted  in  small  frames  upon  the  ground. 
At  first  sight  this  seems  a  very  dangerous  thing  to 
do,  to  allow  shunters  out  of  doors  to  interfere  with 
the  points,  but  all  danger  is  provided  against  in  a 
perfectly  satisfactory  manner.  When  he  wishes  to 
"  make  a  shunt  "  the  shunter  pulls  over  one  lever 
half-way.  He  can  do  no  more  than  this,  for  the 
moment. 

If  the  signalman  knows  that  all  is  right  and  that 
the  shunting  may  safely  take  place,  he,  too,  pulls 
over  a  lever  in  the  cabin,  which  action  causes  a 
current  to  flow  and  to  unlock  the  levers  in  the  ground- 
frame.  The  shunter  can  then  complete  the  move- 
ment of  his  lever  and  proceed  with  the  shunting.  But 
that  is  not  the  whole  story  ;  the  completion  of  its 
movement  by  the  lever  in  the  ground-frame  "  back- 
locks  "  certain  levers  in  the  cabin,  in  other  words, 
locks  them  so  that  they  cannot  be  moved  until  the 
shunting  is  complete,  when,  by  a  similar  series  of 
movements,  the  ground-frame  is  locked  once  more 
and  the  levers  in  the  cabin  freed. 

Certain  parts  of  the  lines  are  protected  by  means  of 
"  track  circuits,"  which  have  already  been  explained 
in  detail  under  the  heading  of  "  automatic  signall- 
ing." It  is  sufficient  here  to  remind  the  reader  that 
the  effect  of  a  track  circuit  is  to  cut  off  a  current 
of  electricity  which  normally  flows  to  the  signal  box 
as  soon  as  a  vehicle  of  any  sort  enters  the  piece  of 
line  which  the  track  circuit  is  to  protect.  For  example, 
take  the  case  mentioned  just  now,  where  a  train  is 
standing  at  the  remote  end  of  a  platform.  It  would 

197 


SIGNALLING  OF  A  LARGE  TERMINUS 

be  possible  for  a  signalman  to  forget  that  it  was 
there  and  to  lower  the  signal  to  allow  a  second  train 
to  enter.  If,  however,  the  line  alongside  the  platform 
be  track  circuited  the  train  standing  there  cuts  off 
current  from  the  signal  box  and  so  causes  the  corre- 
sponding signal  to  be  locked,  so  that  the  signalman 
cannot  lower  it. 

The  track  circuits  are  also  made  to  actuate 
illuminated  diagrams  in  the  signal  box.  These  are 
diagrams  of  the  lines  over  which  the  signalman  has 
control,  divided  up  into  sections,  behind  each  of 
which  is  a  small  electric  light.  When  a  section  is 
free  the  lamp  behind  it  lights  up,  but  as  soon  as  a 
vehicle  of  any  sort  enters  it,  and  so  long  as  it  remains 
there,  the  light  goes  out.  Thus,  by  a  glance  at  the 
diagram,  the  signalman  can  see  which  sections  are 
clear  and  which  occupied.  There  are  two  of  these 
diagrams  in  the  signal  cabin  under  consideration. 

In  a  previous  chapter  on  signalling  the  locking  of 
facing  points  was  described,  and  it  will  be  remembered 
that  two  levers  were  required,  one  to  lock  and  unlock 
and  the  other  to  set  the  points.  In  the  electro, 
pneumatic  system  installed  at  Glasgow  Central  the 
pneumatic  motor  is  made  to  perform  both  operations 
together  in  a  beautifully  simple  manner.  The  air 
enters  and  the  piston  commences  to  move  ;  the  first 
2  ins.  or  so  of  movement  is  employed  in  drawing 
back  the  bolt  and  so  unlocking  the  points,  the  next 
part  of  the  stroke  moves  the  points  over  and  the 
third  part  re-locks  them  in  their  new  position. 

In  addition  to  this,  the  signalman  is  not  able,  at 
first,  to  put  his  lever  right  over.  He  finds  it  physically 

198 


SIGNALLING  OF  A  LARGE  TERMINUS 

impossible  to  do  so  ;  it  simply  will  not  go  right  over. 
He  has  to  wait  until  the  motor  has  done  its  work  ; 
then,  and  then  only,  does  it  send  back  to  the  box  a 
"  return  indication,"  which  permits  the  man  to 
complete  the  movement  of  his  lever.  And,  of  course, 
it  is  only  when  the  movement  is  completed  that  the 
signals  are  unlocked  so  that  he  can  let  a  train  through 
to  the  points.  Assurance  is  thus  made  doubly  sure 
that  no  train  can  approach  facing  points  until  they 
have  been  correctly  set  and  locked. 

Another  feature  of  this  system  is  known  as  "  con- 
stant detection."  Should  anything  happen  to  derange 
the  points  after  they  have  been  set,  the  signal  is 
automatically  put  to  danger,  or  if  it  is  already  at 
danger  is  locked  in  that  position. 

The  compressed  air  is  obtained  from  an  electrically 
driven  compressor,  with  a  steam-driven  one  as 
"  stand-by  "  in  case  of  accident.  The  electric  current 
:s  obtained  from  storage  batteries  periodically  charged 
up  by  means  of  suitable  machinery  installed  for  the 
purpose.  . 

Thus  we  see  how  the  modern  railway  provides  for 
the  safety  of  its  passengers,  but  it  would  be  unfair 
not  to  mention  how  it  cares,  too,  for  its  employes. 
The  signal  box  of  which  we  have  been  speaking  is 
fitted  up  with  every  convenience  for  making  the 
lives  of  the  signalmen  as  comfortable  as  possible 
while  they  are  at  work. 

One  ought  not  to  forget,  too,  the  men  themselves 
who  have  to  work  and  to  maintain  this  wonderful 
signalling  machine.  To  work  it  needs  a  clear  brain, 
well  trained  by  long  experience.  True,  it  is  so 

199 


SIGNALLING  OF  A  LARGE  TERMINUS 

arranged  that  a  novice  even  could  hardly  cause  an 
accident,  but  he  would  never  get  any  trains  in  or 
out.  To  stand  for  a  few  moments  in  a  signal  box 
like  this  is  impossible  without  a  strong  feeling  of 
admiration  for  the  clear-headed,  reliable  men  upon 
whom  the  safety  and  celerity  of  the  train  service 
so  largely  depends. 


200 


CHAPTER  XV 
RAILWAYS  IN  FOGGY  WEATHER 

IT  is  a  mistake  to  assume  that  fog  is  the  result 
of  damp  only.  The  water-vapour  often  present 
in  air  cannot  condense  into  those  fine  drops 
which  constitute  fog  unless  there  be  present  a 
quantity  of  dust  or  other  solid  particles  around 
which  the  droplets  can  form.  Unfortunately,  particles 
of  soot  serve  this  purpose  exceedingly  well,  with  the 
result  that  the  smoke  which  arises  from  the  in- 
numerable chimneys  of  a  populous  town  assists 
materially  in  producing  fog  and  also  makes  such  fog 
peculiarly  dirty  and  opaque. 

Hence,  just  at  those  spots  where  railway  traffic  is 
likely  to  be  most  congested,  dense  and  frequent 
fogs  are  likely  to  occur.  This  is  particularly  dis- 
concerting to  the  railway  manager,  for  it  brings 
to  nought  many  of  his  most  carefully  planned  schemes 
for  the  safe  and  quick  working  of  the  trains. 

Since  a  driver  cannot  see,  or,  at  all  events,  can  only 
see  faintly,  in  foggy  weather,  audible  signals  have  to 
be  given  to  him  in  place  of  the  usual  visible  ones, 
from  which  fact  arises  the  use  of  the  well-known 
fog  signal. 

This  is  a  little  tin  box,  not  unlike  those  tin  boxes 
which  are  made  to  contain  vaseline,  boot  polish  and 

201 


RAILWAYS  IN  FOGGY  WEATHER 

similar  pasty  substances.  Inside  it  are  three  little 
iron  pegs  which  stand  in  an  upright  position  with  a 
percussion  cap  on  the  top  of  each.  In  addition  there 
are  a  few  grains  of  gunpowder,  while  to  the  bottom 
of  the  case  is  soldered  a  short  strip  of  thin,  flexible 
metal  by  which  the  "  detonator,"  to  give  it  its  official 
title,  can  be  clipped  upon  the  rail. 

As  soon  as  a  fog  comes  on,  a  number  of  employe's 
of  the  line,  mostly  platelayers,  repair  to  certain 
appointed  places  where  they  report  to  a  stationmaster 
or  other  official.  This  official  assigns  to  each  man  a 
special  position,  generally  at  the  foot  of  a  certain 
signal  post,  and  issues  to  him  a  supply  of  detonators. 
The  man,  having  reached  his  post,  finding  a  signal 
at  danger,  places  a  detonator  on  the  line  and  leaves 
it  there  so  long  as  the  signal  is  up.  If  the  signal  falls 
he  takes  up  the  detonator.  If  a  train  comes  along 
and  explodes  the  detonator  he  calls  to  the  driver 
when  the  signal  has  fallen  that  he  may  proceed. 
As  soon  as  it  has  gone  and  the  signal  has  been  restored 
to  the  danger  position  he  puts  a  new  detonator  down. 

The  practice  varies  somewhat,  but  in  many 
places  two  are  put  down  instead  of  one  to  guard 
against  the  possibility  of  failure. 

Where  there  is  only  one  arm  on  a  post  and  no  other 
posts  near,  the  "  fogman,"  as  he  is  called,  only  has 
one  line  to  look  after,  but  if  there  be  several  signals 
on  the  same  post  or  near  together,  he  may  have  to 
look  after  several. 

In  case  the  fog  should  last  a  long  time  there  is 
usually  provided  a  rough  shelter  of  some  sort  for 
the  man,  and  the  means  of  making  and  keeping  up 

202 


RAILWAYS  IN  FOGGY  WEATHER 

a  fire.  On  a  foggy  night  the  fogman's  hut  and  fire 
frequently  look  to  the  passing  traveller  very  cosy 
and  comfortable,  but  the  writer  can  assert  from 
practical  experience  of  somewhat  similar  conditions 
that  the  comfort  is  chiefly  apparent. 

Of  recent  years  much  has  been  done  to  improve 

DETONATOR 


Fig.  16. — DIAGRAM  SHOWING  HOW  THE  "FOGGING  MACHINE" 
WORKS. 

In  position  (1)  the  arm  is  holding  the  detonator  on  the  line. 

In  position  (2)  the  detonator  is  being  held  clear  of  the  line, 
the  signal  being  at  "line  clear." 

In  position  (3)  the  arm  has  swung  right  back  to  pick  out  a 
fresh  detonator  from  the  magazine. 

The  spent  detonator  is  dropped  as  the  arm  swings  back 
between  position  (2)  and  (3). 

upon  this  rather  primitive  method  of  fog  signalling, 
at  all  events  in  busy  places. 

For  one  thing,  there  is  a  machine  actually  connected 
to  the  signal  mechanism,  so  that  an  arm  shoots  for- 
ward and  holds  a  detonator  upon  the  line  so  long  as 
the  signal  is  up,  but  withdraws  it  when  the  signal 

203 


RAILWAYS  IN  FOGGY  WEATHER 

falls.  Or  to  be  more  precise,  it  holds  two  detonators 
and  not  simply  one.  It  is  not  quite  automatic, 
however,  because  when  the  detonators  have  been 
exploded  a  man  has  to  place  others  in  the  clips  at 
the  ends  of  the  arms. 

Another  interesting  little  contrivance  may  be 
mentioned  in  this  connection,  although  its  purpose 
is  not  to  help  the  men,  but  to  save  detonators.  It 
consists  of  a  little  arm  with  a  clip  at  the  end  capable 
of  holding  a  detonator.  This  arm  is  fixed  at  one 
end  of  a  rod  a  few  feet  long,  to  the  other  end  of 
which  is  attached  a  strip  of  thin  sheet  iron.  The 
sheet  iron  is  placed  close  to  the  spot  where  a  detonator 
is  fixed  upon  the  rail,  while  the  little  arm  holds 
another  detonator  on  the  same  rail  a  few  feet  further 
on.  If  the  first  detonator  goes  off  the  explosion 
blows  against  the  piece  of  sheet  iron,  causes  the  rod 
to  turn  and  so  lifts  the  second  detonator  clear  of  the 
rail.  Thus,  if  the  first  fails  to  go  off  the  second 
detonator  comes  into  operation,  but  if  the  first  does 
its  duty  the  second  is  not  wasted. 

Generally  speaking  the  fogman  assures  himself  of 
the  state  of  the  signal  by  watching  the  movement 
of  the  balance- weight  near  the  foot  of  the  post.  He 
may,  of  course,  if  the  fog  is  not  very  bad,  be  able  to 
see  the  arm,  or  he  may  even,  in  exceptional  cases, 
have  to  climb  the  post. 

In  busy  places  Clayton's  fogging  machine  is  used, 
in  conjunction  with  little  "  fogging "  arms  low 
down  on  the  post.  The  fogging  arms  are  very  small 
compared  with  those  above,  but  they  are  large 
enough  for  the  purpose  and,  being  mechanically 

204 


RAILWAYS  IN  FOGGY  WEATHER 

connected  to  the  larger  ones,  they  form  perfectly 
reliable  indicators,  enabling  the  fogman  to  tell 
easily  and  with  certainty  what  the  invisible  arms  at 
the  top  of  the  post  are  doing. 

On  large  posts  with  a  number  of  arms,  such  as  we 
often  see  near  large  stations,  there  will  be  a  similar 
number  of  fogging  arms,  and  close  by  there  will 
generally  be  seen  a  small  frame,  with  a  number  of 
little  hand  levers,  like  those  in  the  signal  box,  only 
smaller.  There  will  be  one  lever  for  each  fogging 
arm,  or,  in  other  words,  for  each  signal  on  the  post. 

From  these  levers  rods  run  in  various  directions 
to  the  "  fogging  machines,"  each  of  which  is  close 
to  the  line  upon  which  it  operates. 

Normally  the  machine  shuts  up  into  a  small 
compass  and  is  covered  with  a  light  iron  cover  to 
protect  it  from  the  weather,  but  when  required 
the  cover  is  removed,  the  mechanism  opened  out, 
and  all  is  ready  for  work  in  a  few  seconds. 

The  essential  part  of  the  machine  is  a  cleverly 
contrived  arm  and  hand.  The  hand  has  two  fingers, 
or  a  finger  and  thumb,  with  which  it  can  grasp  a 
little  metal  tab  upon  the  detonator.  By  this  means, 
in  one  of  its  positions,  it  holds  the  detonator  upon 
the  line,  so  that  a  passing  engine  or  vehicle  would 
explode  it. 

Now  suppose  the  signal  is  lowered.  The  fogman 
sees  the  corresponding  fogging  arm  move,  so  he 
places  his  hand  upon  the  corresponding  lever  and 
moves  it  into  its  middle  position ;  perhaps  it  should 
have  been  explained  that  each  of  these  levers  can 
be  placed  in  three  positions. 

205 


RAILWAYS  IN  FOGGY  WEATHER 

The  lever  being  in  the  middle  position,  the  arm 
also  swings  into  its  middle  position,  under  which 
conditions  the  detonator  is  held  clear  of  the  line. 
As  soon  as  the  signal  goes  to  danger  again  the  man 
replaces  the  arm  in  the  first  position,  and  the 
detonator  is  held  over  the  rail  once  more. 

Let  us  suppose,  now,  that  a  train  passes  over  the 
detonator  and  explodes  it.  What  is  to  be  done 
then  ?  The  man  simply  pulls  his  lever  into  the  third 
position,  by  doing  which  he  causes  the  arm  to  swing 
round  to  where  the  reservoir  is  containing  the  supply 
of  detonators. 

This  reservoir  is  a  small,  square,  vertical  column, 
very  like  that  part  of  an  "  automatic  machine  " 
which  holds  the  packets  of  sweets.  In  it  the  deto- 
nators are  packed,  one  above  another,  there  being 
a  space  through  which  the  bottom  one  can  be  readily 
drawn  out,  and  every  time  one  is  taken  the  whole 
pile  drop  down,  so  that  a  new  one  takes  its  place. 

The  beauty  of  the  thing,  judged  as  a  piece  of 
mechanism,  is  that  as  the  arm  swings  back  the 
hand  opens  and  drops  the  spent  detonator,  after 
which  it  clips  firmly  hold  of  a  new  one.  The  lever 
can  then  be  moved  back  to  either  the  first  or  the 
middle  position  as  required,  carrying  the  new 
detonator  with  it,  all  ready  to  do  its  work. 

It  is  easy  to  see  the  advantages  of  this  mechanical 
method  of  handling  fog  signals.  It  enables  one  man 
to  do  the  fog  signalling  on  a  considerable  number 
of  lines,  and  it  enables  him  to  do  it,  moreover, 
without  the  danger  of  having  to  grope  about  crossing 
the  lines  in,  perhaps,  worse  than  pitch  darkness. 

206 


RAILWAYS  IN  FOGGY  WEATHER 

The  consideration  of  the  arrangements  for  fog 
signalling  naturally  lead  to  the  question,  "  Why  is 
there  not  some  way  of  indicating  to  the  driver  upon 
his  engine,  if  the  signals  are  against  him  or  not  ?  " 
The  device  of  letting  off  fireworks  under  the  engine 
certainly  seems  crude,  and  it  may  be  that  it  is  in 
process  of  being  done  away.  At  all  events,  there 
have  been  many  suggestions  for  "  cab  signals,"  that 
is,  definite  signals  of  some  sort  in  the  cab,  which 
would  make  a  driver  independent  of  fog  signals  of 
the  usual  type.  Of  these  various  suggestions  we  will 
notice  first  the  one  associated  with  the  name  of 
Sykes,  a  name  well  known  as  that  of  one  of  the 
pioneers  in  the  use  of  electricity  for  railway  signalling. 
The  following  is  a  description  of  the  "  Sykes  audible 
cab  signal." 

It  consists  of  two  parts,  one  upon  the  line, 
called  the  "  ramp "  and  the  other  upon  the 
engine. 

The  term  "  ramp  "  means,  in  engineering  language, 
an  incline,  and  in  this  case  it  indicates  a  length  of 
T-iron  which  is  placed  with  the  stem  of  the  T  upwards 
on  the  ground  between  the  rails.  It  is  bent  slightly 
towards  the  middle,  so  that  it  slopes  slightly  upwards 
from  either  end  and  then  falls  away  again.  It  is 
firmly  fixed  in  specially  designed  chairs,  which  are 
in  turn  secured  to  the  sleepers.  Moreover,  for  a 
reason  which  will  be  apparent  presently,  it  is 
electrically  insulated. 

The  apparatus  beneath  the  engine,  which  is  spoken 
of  as  the  "  under-gear,"  appears  to  be  a  wrought- 
iron  box,  from  the  bottom  of  which  there  projects 

207 


RAILWAYS  IN  FOGGY  WEATHER 

a  strong  iron  slide  with  a  shoe  made  of  specially 
hardened  iron  at  its  lower  extremity. 

This  shoe  is  also  insulated  electrically,  from  which 
it  will  be  gathered  that  it  has  an  electrical  function 
of  some  sort,  but  for  the  moment  we  will  consider 
its  purely  mechanical  purpose.  This  is  to  slide  up 
the  ramp  as  the  engine  passes  over  it. 

Striking  the  ramp  near  its  lowest  point  it  is  raised 
as  the  ramp  rises,  until,  having  passed  the  highest 
point  the  ramp  permits  it  to  fall  again. 

If,  then,  one  of  these  ramps  be  placed  near  to  each 
signal,  the  shoe  upon  a  passing  engine  will  inevitably 
be  raised  as  it  goes  by.  The  raising  of  the  shoe  will 
lift  the  slide  and  the  motion  of  the  slide  can  be  made 
to  do  certain  things. 

Let  us  now  imagine  the  cover  to  be  lifted  off  the 
"  box  "  from  which  the  slide  projects.  There  we 
see  a  number  of  small  rods  and  levers,  two  little 
cylinders  and  an  electro-magnet. 

One  cylinder  is  connected  by  a  pipe  to  the  "  train 
pipe,"  which  supplies  the  brakes  throughout  the 
train  with  compressed  air.  This  air,  acting  upon  a 
piston  in  the  cylinder  is  always  pressing  one  of  the 
levers  in  a  certain  direction,  but  the  lever  cannot 
move  because  of  a  "  trigger-like "  arrangement 
designed  to  prevent  it. 

When  the  plunger  rises,  however,  it  "  pulls  the 
trigger,"  so  to  speak,  releases  the  lever  and  allows  the 
compressed  air  to  push  it  forward.  That,  in  turn, 
allows  the  compressed  air  to  escape,  with  the  result 
that  the  brake  is  applied  throughout  the  train. 

Thus,  when  the  shoe  passes  over  a  ramp  it  is 

208 


rt 

*t 

-o  ^ 

1 1 


RAILWAYS  IN  FOGGY  WEATHER 

raised,  that  operates  the  plunger,  which  releases 
the  trigger,  liberates  the  compressed  air  and  puts 
on  the  continuous  brake. 

All  the  apparatus  for  this,  be  it  noted,  is  very 
robust  and  strong,  its  action  is  very  simple,  it  is 
inconceivable  that  it  could  get  out  of  order,  and  so 
can  be  safely  relied  upon  to  give  warning  of  danger. 

The  air,  the  escape  of  which  puts  on  the  brakes, 
is  led  away  through  a  pipe  to  a  whistle  on  the  cab, 
so  that  in  the  event  of  his  overrunning  a  signal  a 
driver  not  only  finds  his  brakes  go  on,  but  also 
hears  a  shrill  whistle  close  to  his  ear. 

All  that  happens,  if  the  signal  is  at  danger.  When 
it  is  at  "  line  clear  "  events  take  a  different  course, 
due  to  the  action  of  a  feeble  electric  current. 

There  is  a  wire  running  from  the  signal  cabin  to 
the  "  ramp."  There  is  also  a  switch  attached  to 
the  lever  in  the  cabin,  so  arranged  that  when  the 
lever  is  normal  the  switch  is  open,  but  when  it  is 
reversed  (to  lower  the  signal)  the  switch  is  closed. 
The  switch  is  only  closed,  then,  when  the  line  is 
clear.  The  closing  of  this  switch  connects  a  battery, 
through  the  wire,  to  the  ramp. 

Under  these  conditions  the  slide  is  raised  as  before 
and  the  trigger  is  released,  but  the  electric  current, 
passing  from  the  ramp  to  the  shoe,  flows  up  into 
the  box  and  energizes  the  electro-magnet.  This 
magnet,  when  energized,  prevents  the  lever,  although 
released  by  the  trigger,  from  moving.  The  trigger, 
therefore,  falls  back  again  into  its  normal  state, 
nothing  having  happened. 

Thus,  whereas  the  passage  of  an  engine  over  a 
o  209 


RAILWAYS  IN  FOGGY  WEATHER 

"  dead "  ramp  stops  the  train,  passage  over  an 
"energized"  ramp  has  no  effect  at  all,  for  the 
mechanical  effect  of  raising  the  slide  is  neutralized 
by  the  action  of  the  electric  current  in  energizing 
the  magnet. 

Just,  however,  to  let  the  driver  know  that  he  has 
passed  a  signal  at  safety,  the  current,  after  passing 
the  electro -magnet,  is  led  to  an  electric  bell  in  the 
cab. 

The  total  effect  is,  then,  that  if  a  driver  on  a  line 
fitted  with  this  apparatus  were  to  go  on  with  his 
eyes  shut,  on  passing  a  signal  at  "  line  clear  "  he 
would  hear  a  short  ring  upon  the  electric  bell.  When, 
however,  he  came  to  one  at  danger  the  whistle  would 
sound  and  the  brakes  would  go  on. 

But  there  is  still  one  feature  to  be  explained, 
namely,  the  second  of  the  two  cylinders  mentioned. 
It  also  is  connected  to  a  pipe  which  leads  to  a  valve 
in  the  cab,  to  which  valve  is  attached  a  handle, 
called  the  "  re-setting  handle."  When  the  apparatus 
has  applied  the  brakes,  it  is  necessary  to  release 
them  again  before  the  train  can  proceed,  and  this 
can  be  accomplished  by  the  simple  movement  of 
the  "  re-setting  handle."  Its  action  permits  com- 
pressed air  to  enter  this  second  cylinder,  where, 
by  acting  upon  a  piston,  it  pushes  the  whole  con- 
trivance of  rods  and  levers  back  into  its  normal 
state,  re-sets  the  trigger  and  leaves  it  all  ready  for 
action  the  next  time  it  is  required. 

In  this,  as  in  so  many  other  signalling  devices, 
we  see  how  the  electric  current,  uncertain  though  it 
may  be,  is  used  with  safety.  There  are  so  many 

210 


RAILWAYS  IN  FOGGY  WEATHER 

little  things  which  may  upset  the  action  of  an  electric 
current  that  it  is  never  relied  upon  to  give  a  warning 
of  danger.  A  little  dirt  on  some  contacts,  a  slightly 
run-down  battery,  a  little  chafing  of  the  insulation 
on  a  wire,  a  wire  breaking,  many  little  things  may 
possibly  cause  an  electric  current  to  fail.  The  result 
is  not  serious,  however,  if  things  be  so  arranged  that 
failure  indicates  danger,  as  is  done  in  the  case  just 
considered. 

The  first  idea  was  that  the  cab  signal  apparatus 
should  be  applied  to  distant  signals  only,  but  there 
is  no  strong  reason  why  it  should  not  be  applied  to 
all  signals  if  that  should  turn  out  to  be  desirable, 
and  for  that  the  makers  have  made  provision. 

It  will  be  remembered  that  at  a  distant  signal  a 
train  does  not  stop  ;  it  only  slows  down  in  order  to 
be  ready  to  stop,  if  need  be,  at  the  home  signal. 
Hence  the  need  for  a  quick  use  of  the  "  re-setting 
handle." 

But  if  it  were  used  at  home  signals  as  well  as  at 
distant  signals  a  driver  might  "  re-set  "  and  go  on 
past  a  home  signal.  To  prevent  that,  it  is  arranged 
to  make  the  ramp  slightly  higher  at  a  home  signal, 
and  the  extra  lift  of  the  slide  so  alters  the  arrange- 
ments inside  the  box  that  they  cannot  be  re-set  by 
the  re-setting  handle.  Under  those  conditions  the 
driver  has  to  get  off  his  engine  and  re-set  from  the 
ground,  thus  compelling  him  to  stop  his  train  dead. 

Of  course,  this  apparatus  would  work  just  the 
same  in  fine  wreather  as  in  fog,  and  its  advantages 
would  be  by  no  means  small  as  a  safeguard  against 
a  momentary  lapse  upon  the  part  of  a  driver  even 

211 


RAILWAYS  IN  FOGGY  WEATHER 

in  the  finest  weather :  the  historic  accident  at 
Slough,  for  example,  occurred  upon  a  beautiful 
summer  afternoon,  but  it  would  have  been  quite 
impossible  had  this  apparatus  been  installed.  As 
a  matter  of  fact,  it  was  not  even  invented  then. 

Still,  the  chief  benefits  of  the  cab  signals  will  no 
doubt  accrue  when  the  weather  is  foggy. 

A  system  very  similar  to  this  in  its  general  features 
has  been  in  use  on  parts  of  the  Great  Western  Railway 
for  a  considerable  time.  It  has  a  contact  shoe  on 
the  engine  and  a  ramp  between  the  rails,  just  like 
the  arrangement  described  above.  It  also  sounds  a 
whistle  and  applies  the  brake  in  case  of  danger, 
and  rings  a  bell  in  the  event  of  the  indication  being 
"  clear."  The  difference  between  the  two  systems 
is  in  details. 

In  both  these  arrangements,  it  will  be  noticed, 
the  driver  has  to  rely  upon  some  other  source  of 
information  to  let  him  know  when  the  time  comes 
to  proceed  after  having  been  stopped.  He  has  to 
find  this  out  as  best  he  can  from  the  visible  signal. 

In  the  "  Raven "  system,  used  on  the  North- 
Eastern  Railway,  even  this  difficulty  is  removed. 
In  this  case  the  engine  passes  over  a  series  of  as 
many  as  five  ramps,  one  after  another. 

In  the  driver's  cab  there  is  a  small  model  signal 
arm  enclosed  in  a  glass  case.  The  signals  are  conveyed 
to  the  driver  by  these,  but  in  order  that  he  may  be 
saved  the  necessity  of  continually  watching  this 
indicator  a  bell  is  employed  as  well. 

The  first  ramp  is  placed  about  150  yards  before 
the  train  reaches  a  distant  signal.  That  one  always 

212 


[RAILWAYS  IN  FOGGY  WEATHER 

causes  the  bell  to  ring  and  the  small  arm  to  go  to 
danger.  If,  on  reaching  the  distant  signal,  all  the 
signals  are  "  off  "  for  the  train  to  proceed  into  the 
next  section,  the  arm  falls  and  the  bell  ceases  to 
ring.  This,  of  course,  is  due  to  the  action  of  the 
second  ramp,  which  is  near  the  distant  signal.  If, 
however,  the  home  signal  is  still  "  on  "  or  at  danger, 
when  the  train  reaches  the  distant  signal,  the  arm 
remains  up  and  the  bell  continues  to  ring.  The 
driver,  therefore,  proceeds  cautiously,  passing  over 
a  third  ramp,  during  which  the  bell  ceases  for  a 
moment  (the  arm  still  remaining  at  danger)  until 
he  reaches  the  fourth  ramp,  when,  if  the  indications 
are  still  against  him,  he  stops.  The  cessation  of  the 
bell  signals  while  passing  over  a  ramp  are  intended 
to  tell  him  just  where  he  is,  and  to  enable  him  to 
stop  exactly  over  the  fourth  ramp,  thereby  keeping 
him  in  touch  with  the  signalman. 

The  signalman  can  thus  give  him  the  order  to 
proceed  at  any  moment,  the  indication  to  the  driver 
being  the  falling  of  the  little  signal  arm  and  the 
complete  cessation  of  the  bell.  Or  he  can  give  him 
the  "  calling-on  "  indication,  whereby  he  is  instructed 
to  draw  ahead  slowly  as  far  as  the  starting  signal. 
The  signalman  gives  this  instruction  by  working  a 
switch  in  his  cabin,  which  causes  the  small  arm  on  the 
engine  to  go  up  and  down  several  times. 

If  he  is  thus  "  called-on  "  the  driver  proceeds  as 
far  as  the  fifth  ramp,  over  which  he  brings  his  engine 
to  a  stand  and  from  which  he  gets  his  final  signal 
to  proceed. 

The  simple  apparatus,  employed  in  connection 

213 


RAILWAYS  IN  FOGGY  WEATHER 

with  the  automatic  signals  on  the  London  Under- 
ground and  elsewhere,  is  described  in  another  chapter, 
and  there  is  a  further  device  of  a  very  simple  character 
employed  on  some  of  the  open  parts  of  the  "  Under- 
ground "  lines  to  assist  the  drivers  in  case  of  fog. 
This  consists  of  a  powerful  pair  of  electric  lights, 
one  red  and  one  green,  placed  by  the  side  of  the 
line.  When  either  of  these  lamps  is  "  alight  "  it 
causes  a  coloured  glow  in  the  fog,  which  can  be 
seen  by  a  driver  quite  a  considerable  distance  away. 


214 


CHAPTER  XVI 
TRAFFIC  CONTROL 

IT  frequently  happens  that  a  train  on  a  branch 
line  has  to  wait  near  the  junction,  while  trains 
are  running  through  on  the  main  line,  and  in 
such  cases  the  branch  passengers  usually  grumble 
and  complain. 

As  a  matter  of  fact,  if  they  would  but  consider  the 
difficulties  of  managing  the  vast  traffic  of  a  busy 
line  they  would  be  surprised,  not  that  there  is  delay 
to  a  train,  but  that  the  trains  ever  got  through  at  all. 

When  you  come  to  think  of  the  way  in  which  the 
trains  pass  through  a  busy  junction  first  one  way, 
then  another,  first  along  one  line  and  then  along 
another,  it  is  astounding  that  they  interfere  with 
each  other  so  little. 

As  far  as  passenger  traffic  is  concerned  control 
takes  the  form  of  working  as  closely  as  possible  to  a 
prearranged  schedule.  The  time  tables  are  carefully 
worked  out  so  as  to  allow  the  necessary  interval 
between  trains  ;  branch  line  trains  are  timed  to 
arrive  at  junctions  just  when  there  is  a  suitable 
interval  in  the  main  line  traffic,  and  so  on.  So  long 
as  every  train  is  able  to  keep  time  correctly  there  is 
little  need  for  any  other  form  of  control.  The  control 
is  really  exercised  when  the  time  tables  are  drawn  up. 

215 


TRAFFIC  CONTROL 

In  actual  practice,  of  course,  all  manner  of  things 
happen  to  cause  delay  to  trains,  delay  which  it  is 
quite  impossible  to  foresee.  Fog  may  settle  over  a 
large  area  and  disorganize  all  the  traffic.  Or  it  may 
affect  a  small  area  with  almost  equally  bad  results, 
for  delay  in  one  spot  soon  makes  its  results  felt  all 
over  a  large  system.  The  same  may  follow  from  a 
small  defect  in  some  signalling  apparatus  or  some 
part  of  the  permanent  way. 

As  an  example  of  this,  one  day,  some  years  ago, 
a  passenger  threw  a  small  article  out  of  a  carriage 
window  near  a  small  station  on  the  south  coast  of 
England.  It  happened  to  fall  on  the  points  of  a 
branch  line,  so  that  when  the  signalman  tried  to 
operate  them  from  his  cabin  he  could  not  do  so,  but 
had  to  send  to  see  what  was  the  matter  and  put  it 
right.  This  only  took  a  few  minutes,  but  it  was 
long  enough  to  delay  a  train,  and  that  delay  made 
itself  felt  as  far  away  as  the  London  Terminus  of 
the  line. 

Thus  we  see  that  as  soon  as  anything  goes  a  little 
wrong,  a  thing  which  may  easily  happen,  the  need 
arises  for  some  mind  or  minds  to  take  control  and 
readjust  the  arrangements  to  suit  the  new  con- 
ditions. 

In  this  the  stationmasters  play  a  large  part.  The 
traffic  passing  through  a  station  is  very  largely  under 
the  stationmaster's  control.  He  has  authority  to  do 
what  may  seem  to  him  at  the  moment  the  best, 
having  regard  to  the  smooth  working  of  the  line  as 
a  whole.  The  signalmen,  too,  have  a  considerable 
discretion  left  to  them  under  certain  conditions,  so 

216 


TRAFFIC  CONTROL 

Mi, -it,  they  also  can  do  their  part  in  rectifying  un- 
expected difficulties. 

The  weakness  with  this  form  of  control  is,  however, 
that  each  official  can  only  know  what  is  happening 
on  his  own  piece  of  line.  Roughly  speaking,  all  ]«• 
can  do  is  to  get  the  traffic  along  as  expeditiously  as 
possible,  leaving  the  men  further  on  to  do  the  best 
they  can  with  it  in  turn  when  it  reaches  them.  A 
certain  amount  of  collaboration  is  possible  by  tele- 
phone, but  not  a  great  deal. 

Still,  this  form  of  control  by  stationmasters  and 
signalmen  is  perhaps  sufficient  for  passenger  traffic, 
for  there  the  regularity  of  the  service  removes  many 
difficulties.  With  goods  traffic,  however,  it  is  quite 
different. 

Some  goods  trains,  it  is  true,  run  to  schedule  just 
as  the  passenger  trains  do,  but  a  great  many  are  in 
effect  "  specials,"  running  when  needed.  Even 
those  which  are  scheduled  often  have  to  stop  at 
wayside  stations  to  pick  up  or  to  put  off  wagons. 
Most  of  us  at  some  time  or  other  have  seen  a  goods 
train  come  along  to  some  small  station,  proceed 
to  shunt  a  few  trucks  into  one  siding,  a  few  into 
another,  pick  up  some  from  a  third  and,  indeed, 
perform  quite  a  complicated  series  of  movements 
before  once  again  resuming  its  journey.  Obviously, 
such  operations  cannot  be  allowed  for  accurately 
in  a  time  table,  because  the  amount  of  shunting 
necessary  at  each  place  probably  depends  upon  the 
commercial  activity  at  the  moment  of  some  local 
brickworks,  or  stone  quarry,  or  upon  the  quality  of 
the  local  farmers'  crops. 

217 


TRAFFIC  CONTROL 

Goods  trains,  therefore,  often  get  out  of  step,  so 
to  speak,  with  the  regular  stream  of  traffic  and  lose 
their  place  in  the  procession.  Such  a  train  may 
have  to  wait  a  long  time  in  some  siding  until  the 
signalman  has  a  chance  to  slip  it  in  in  a  suitable 
interval  between  two  passenger  trains. 

In  manufacturing  districts  and  most  of  all  in 
colliery  districts,  where  the  goods  and  mineral 
traffic  is  very  heavy,  the  management  of  this  irregular 
traffic  becomes  very  difficult,  so  much  so  that  some 
years  ago  the  Midland  Railway  adopted  a  system 
of  control  extending  all  over  a  very  busy  area, 
operated  from  one  central  point. 

A  marvellous  system  of  telephones  was  installed, 
giving  instant  communication  between  the  controller 
in  his  central  office  and  the  signalmen  at  the  wayside 
stations  all  over  the  area. 

In  order  that  the  trains  might  be  easily  identified, 
each  engine  had  its  number  painted  upon  it  or  upon 
its  tender  in  huge  figures,  large  enough  to  be  read 
from  any  reasonable  distance,  a  custom  which  has 
since  spread  throughout  most  of  the  British  railway 
systems. 

Seated,  then,  in  his  office,  the  controller  moves  the 
trains  about  almost  like  a  chess-player  with  his 
"  men."  He  knows  at  each  moment  within  a  mile 
or  so  where  a  train  is,  can  stop  it  or  start  it,  divert 
it  to  one  line  or  another,  just  as  seems  to  him  best, 
and  by  that  means  he  can  get  the  whole  of  the 
traffic  moving  in  the  most  expeditious  manner. 

Since  then,  the  same  system  has  been  adopted 
upon  other  lines,  and  even  electric  street  railways 

218 


TRAFFIC  CONTROL 

or  tramways  have  in  places  adopted  it  in  order  to 
deal  quickly  with  obstructions  and  breakdowns. 

Now  it  will  be  seen  that  the  whole  success  of  this 
method  of  control  depends  on  the  telephone.  It 
must  be  so  arranged  that  the  controller  is  in  constant 
touch  with  his  men  all  over  his  area  ;  he  must  be 
almost  as  free  to  speak  to  them  and  they  to  him  as 
if  they  were  assembled  in  the  same  room.  The 
original  installation  on  the  Midland  achieved  this 


5 


SELECTION  KEYS    IN  SELECTORS   (N   CABINS    AT 

CONTROLLERS  OFFICE  WAYSIDE     STATIONS 

Fig.  17. 

This  simple  diagram  shows  how  all  the  signal  cabins  in  the 
controlled  area  are  connected  to  the  Controller's  Office  by  a 
single  pair  of  wires. 

Key  1  sends  out  a  certain  series  of  impulses,  to  which  only 
Selector  1  can  respond.  In  the  same  way,  Key  2  calls  up  only 
Selector  2,  and  so  on.  The  controller's  telephone  is  indicated 
on  the  left.  The  local  telephones  are  not  shown — each  man 
switches  himself  in  when  called  by  his  selector. 


by  a  multiplicity  of  lines  and  special  code  signals, 
but  since  that  was  installed  the  need  for  a  simpler 
scheme  has  called  into  being  one  of  the  most  wonder- 
ful telephone  systems  ever  invented.  It  was  designed 
by  the  Western  Electric  Company  specially  for  this 
particular  purpose. 

Let  me  introduce  you  to  the  G.N.R.  Control  Room 
at  Leeds.  It  is  a  large,  airy  apartment,  not  elaborately 
furnished,  but  clean,  warm  and  well  suited  for  the 
purpose.  Along  one  wall  is  a  large  diagram  showing 

219 


TRAFFIC  CONTROL 

clearly  the  whole  of  that  part  of  the  Great  Northern 
system  which  is  controlled  from  this  station. 

Facing  this  diagram,  sit  four  men.  Each  has  his 
arm-chair  and  knee-hole  desk,  the  desks  being 
spaced  at  equal  distances  opposite  the  long  diagram. 
Each  of  these  men  is  a  controller,  and  his  duty  is 
to  control  the  traffic  upon  the  lines  represented  upon 
that  part  of  the  diagram  before  which  he  sits. 

Upon  his  desk,  to  his  left  hand,  is  a  neat  polished 
wood  case  with  rows  of  little  turn-buttons  on  the  front, 
each  button  being  distinguished  by  an  ivory  label. 

Upon  his  head  each  controller  wears  a  telephone 
instrument  similar  to  those  worn  by  the  operators 
in  a  telephone  exchange. 

The  diagram  upon  the  wall  is  perforated  with 
small  sockets  into  which  can  be  pushed  small  plugs 
with  variously  coloured  heads  ;  each  plug  represents 
a  train,  and  the  colour  shows  the  kind  of  train, 
whether  passenger,  goods,  mineral  and  so  on.  Thus 
the  controller  has  always  before  him  an  actual  repre- 
sentation of  the  line  with  the  positions  of  the  trains 
at  any  moment  represented  by  the  plugs,  the 
latter  being,  of  course,  changed  continually  as  the 
news  comes  in  of  the  arrivals  of  the  trains  at  the 
successive  points  in  their  journeys. 

As  a  train  approaches  the  edge  of  an  area  the 
controller  for  that  area  confers  with  his  colleague 
at  the  next  desk,  and  ultimately  hands  the  train 
over  to  him. 

Thus  we  see  the  operation  of  the  system  in  the 
control  room.  Let  us  now  transfer  ourselves  to  a 
signal  box  in  the  controlled  area. 

220 


TRAFFIC  CONTROL 

A  train  approaches,  the  signalman  goes  to  the 
telephone  and  without  any  preliminaries  just  an- 
nounces that  train  number  so  and  so  is  passing. 
There  is  no  need  for  the  signalman  to  ring  up,  for 
the  controller  always  has  his  headgear  on,  and  any 
signalman  on  a  section  can  thus  speak  to  him  at  any 
moment  almost  as  if  they  were  in  the  same  room. 

On  hearing  of  the  passing  of  the  train  the  con- 
troller calls  out  the  fact  to  a  colleague,  who  makes 
the  necessary  movement  of  a  plug  on  the  diagram. 
Meanwhile,  the  controller  is  thinking,  and  he  decides, 
shall  we  say,  that  this  particular  train  had  better 
be  held  up  at  the  next  station  to  give  a  faster  train 
precedence.  He,  therefore,  puts  out  his  left  hand 
and  gives  one  of  the  turn-buttons  a  quarter -turn. 
That  is  all  he  does,  but  the  effect  is  that  within  a 
few  seconds  he  hears  the  signalman  at  the  station 
which  the  train  is  approaching  "  come  on  the  line." 
To  him  he  gives  the  necessary  instructions  how  he 
is  to  dispose  of  the  train  when  it  reaches  him. 

Of  course,  the  working  of  all  the  trains  over  a 
large  area  is  not  completely  represented  by  this 
simple  illustration.  On  the  contrary,  it  is  a  very 
complicated  business,  calling  for  a  very  clear  head 
and  active  brain,  and  the  controller  must  be  a  man 
of  ingenuity,  resource  and  quick  decision.  Still,  the 
illustration  serves  to  give  an  idea  of  how  the  system 
works. 

Now  the  remarkable  thing  is  that  all  this  inter- 
communication is  entirely  accomplished  by  means  of 
two  wires. 

These  two  wires  run  from  the  controllers'   desk 

221 


TRAFFIC  CONTROL 

through  all  the  instruments  at  all  the  signal  boxes 
which  come  under  his  supervision. 

All  the  instruments  are  connected  in  the  same  way 
between  these  two  wires,  and  were  they  ordinary 
electric  bells  the  effect  of  pressing  a  key  in  the  con- 
troller's office  would  simply  be  to  ring  them  all. 
It  would,  of  course,  be  possible  even  then  to  use  a 
code  of  bell  signals,  thereby  indicating  which  par- 
ticular box  was  being  called,  the  others  hearing  the 
signal,  but  ignoring  it. 

That,  however,  would  be  a  nuisance,  for  supposing, 
say,  thirty  signal  boxes  on  one  circuit,  each  one 
would,  on  the  average,  hear  twenty-nine  bell  signals 
to  be  ignored  for  every  one  that  required  attention. 
There  is  another  alternative,  it  is  true,  and  that  is 
to  have  separate  wires  from  the  control  room  to 
each  signal  box,  but  that  entails  very  great  expense, 
not  only  when  the  wires  are  installed,  but  for  upkeep 
and  repairs  as  well. 

In  this  particular  system  both  these  difficulties 
are  overcome  by  the  use  of  special  "  selective " 
instruments. 

The  controller,  as  has  been  said  already,  has  a 
turn-button  for  each  signal  box.  These  are  all 
connected  to  the  same  two  wires.  When  he  gives 
one  a  quarter-turn  he  thereby  winds  up  a  little 
spring,  so  that  when  he  lets  go  it  slowly  turns  back 
again.  It  is  in  turning  back  that  it  does  its  work. 
The  reason  for  this  arrangement  is  that  for  effective 
working  it  is  desirable  that  it  should  turn  at  a  regular 
speed,  and  the  uniform  pressure  of  the  spring  ensures 
this.  No  matter  how  quickly  or  how  slowly  the  man 

222 


TRAFFIC  CONTROL 

may  turn  the  button,  it  comes  back  under  the  in- 
fluence of  the  spring  at  a  regular  and  unvarying 
speed. 

Now  as  it  thus  turns  back  it  rotates  a  set  of  wheels, 
like  those  of  a  stoutly  made  clock.  The  last  of  this 
series  of  wheels  moves  the  end  of  a  little  spring 
finger,  and  this  is  so  arranged  that  whenever  a  tooth 
raises  the  finger  a  contact  is  made  and  a  little  current 
of  electricity  goes  to  one  of  the  pair  of  wires,  through 
ALL  the  instruments  and  back  again  along  the  other 
wire.  Likewise,  whenever  the  end  of  the  finger  falls 
into  a  space  between  two  teeth  it  makes  a  momentary 
contact  and  sends  another  current. 

In  conjunction  with  this  there  works  a  further 
small  device  called  a  "  pole  changer  relay,"  the 
purpose  of  which  is  to  cause  these  little  currents  to 
flow  alternately  first  in  one  direction  and  then  in 
another. 

These  currents  are  so  short  that  it  is  perhaps 
better  to  call  them  impulses,  as  the  term  current 
gives  the  impression  of  a  steady  flow  for  some  appre- 
ciable time. 

A  relay  is  really  an  electrically  operated  switch, 
its  usual  function  being  to  enable  a  feeble  current 
to  switch  on  and  off  a  much  more  powerful  current. 
In  this  case,  however,  its  purpose  is  to  reverse  the 
connections  with  the  battery.  One  impulse,  passing 
through  the  electro-magnet  which  forms  a  part  of 
the  relay,  pulls  over  a  light  switch  into  such  a  position 
that  the  next  impulse  flows  in  the  opposite  direction. 

The  next  impulse  acts  in  the  opposite  way,  thereby 
undoing  what  the  first  one  did,  with  the  result  that 

223 


TRAFFIC  CONTROL 

the  series  of  impulses  sent  out  by  the  "  selector  key," 
as  the  clockwork  device  is  called,  pass  to  the  wire 
alternately  "  positive "  and  "  negative,"  as  the 
telegraph  engineer  terms  it. 

Thus  the  result  of  turning  the  button  and  then 
letting  it  go  is  to  send  through  the  wires  a  series  of 
seventeen  impulses.  It  is  not  quite  clear  why  seven- 
teen was  chosen,  but  no  doubt  that  was  found  to  be 
the  most  convenient  number. 

Alongside  the  wheel  which  sends  out  these  impulses, 
and  capable  of  being  clamped  to  it,  are  two  brass 
discs,  each  of  which  has  a  projection  at  one  part  of 
its  circumference.  This  projection  coming  into  con- 
tact with  the  "  finger  "  causes  it  to  be  held  still, 
and  thereby  interrupts  the  regular  flow  of  impulses. 
Just  where  this  interruption  occurs  in  the  series  of 
seventeen  depends  upon  the  position  in  which  the 
disc  is  clamped  alongside  the  wheel.  By  fixing  the 
two  discs  in  the  correct  positions,  two  intervals  can 
thus  be  produced  at  any  desired  points  in  the  series. 

The  "  selector  keys  "  are,  of  course,  in  that  neat 
little  cabinet  on  the  controller's  desk,  and  they  are 
all  alike  in  every  respect,  except  for  the  positions  of 
the  discs.  Each  of  them,  when  turned  and  then  let  go, 
sends  out  a  series  of  seventeen  impulses,  but  in  each 
one  the  interruptions  occur  in  different  places.  It 
is  the  positions  of  the  intervals  which  enable  each 
key  to  do  its  proper  work. 

Just  to  make  this  quite  clear,  let  us  consider  a 
few  examples  of  seventeen  impulses  with  two  intervals. 
We  can  commence  with  two  impulses,  pause,  two, 
pause,  thirteen.  Then  would  come  naturally  in 

224 


£  5 


TRAFFIC  CONTROL 

sequence,  two,  pause,  three,  pause,  twelve ;  then 
two,  pause,  four,  pause,  eleven,  and  so  on  to  thirteen, 
pause,  two,  pause,  two.  By  varying  the  positions 
of  the  pauses  as  many  as  seventy-eight  different 
"  signals  "  can  be  made. 

And  now  let  us  pass  to  the  "  selectors,"  of  which 
there  is  one  at  every  signal  box.  All  of  them  are 
connected  in  precisely  the  same  way  between  the 
two  wires,  so  that  each  impulse  sent  out  by  a  key 
divides  itself  up  and  passes  equally  through  all. 

Thus  every  time  a  key  is  operated  all  the  selectors 
work,  but  only  one  rings  a  bell. 

This  apparently  miraculous  result  follows  from  the 
position  of  the  pauses  in  the  series  of  impulses  sent 
out  by  the  key. 

The  selector  has,  first  of  all,  an  electro-magnet, 
composed  of  a  soft  iron  core  encircled  by  a  coil  of 
insulated  wire.  This  is  normally  powerless,  but  is 
energized  whenever  a  current  of  electricity  passes 
through  it. 

Against  the  end  of  the  core  is  set  a  permanent 
magnet,  that  is  to  say,  a  piece  of  steel  which  has  been 
so  treated  that  it  has  the  properties  of  a  magnet 
permanently.  Such  a  magnet,  as  most  people  know, 
has  a  North  Pole  and  a  South  Pole.  What  the 
difference  is  nobody  knows  precisely,  but  we  do  know 
that  there  is  a  difference,  and  one  of  the  most  im- 
portant manifestations  of  this  "  polarity  "  is  that 
if  two  magnets  be  brought  near  each  other,  similar 
poles  will  repel  each  other,  while  dissimilar  poles 
will  attract  each  other. 

The  poles  of  a  permanent  magnet  remain  fixed ; 
p  225 


TRAFFIC  CONTROL 

the  poles  of  an  electro-magnet  change  according  to 
the  direction  of  the  current  through  the  coil.  There- 
fore, if  we  set  one  pole  of  a  permanent  magnet 
against  one  pole  of  an  electro-magnet  we  can  cause 
the  latter  to  attract  or  repel  the  former  at  will  by 
simply  changing  the  direction  of  the  current. 

An  arrangement  of  that  sort  is  found  in  the 
"  selector,"  and  the  little  impulses  coming  from  the 
key,  because  of  their  alternate  directions,  alternately 
push  and  pull  upon  a  small  permanent  magnet 
mounted  near. 

The  next  feature  which  demands  our  attention  is 
a  small  wheel,  like  a  wheel  of  a  clock,  which  is  mounted 
upon  a  vertical  axis  near  to  the  magnet.  When  the 
magnet  moves  one  way  a  little  ringer  attached  to  it 
comes  into  contact  with  one  of  the  teeth  of  the  wheel 
and  pushes  it  round  a  little  way.  On  the  current 
being  reversed  the  permanent  magnet  moves  the 
opposite  way,  and  that  is  made  to  operate  another 
finger  which  again  gives  a  push  to  the  wheel,  so  that 
with  each  impulse  the  wheel  is  rotated  one  tooth. 

In  their  normal  position  both  these  fingers  are 
just  clear  of  the  wheel,  so  that  the  wheel  can  turn 
freely  ;  moreover,  there  is  a  spring  which  is  always 
trying  to  pull  the  wheel  back  to  its  normal  position, 
so  that  at  first  sight  it  seems  as  if  the  fingers  would 
do  no  work  at  all.  We  might  expect  that  when  the 
first  finger  had  given  its  push,  as  it  drew  back,  the 
wheel  would  also  turn  back,  and  the  second  finger 
would  only  do  over  again  what  the  first  had  done. 
The  inertia  of  the  wheel,  however,  comes  in  here. 
The  first  finger  pushes  the  wheel,  then  it  suddenly 

226 


TRAFFIC  CONTROL 

draws  back  and  the  second  gives  its  push,  and  the 
second  follows  the  first  so  quickly  that  the  wheel  has 
not  time  to  swing  back.  The  second  finger  catches 
the  wheel  practically  in  the  position  where  the  first 
leaves  it,  and  so  the  two  acting  alternately  can  push 
it  round  to  the  extent  of  seventeen  teeth,  if  they 
continue  to  follow  one  another  sufficiently  rapidly. 

But  when  a  pause  occurs  in  the  series,  the  wheel, 
as  it  is  easy  to  see,  will  swing  back  to  its  starting 
point. 

We  now  come  to  the  next  essential  feature  in  the 
selector.  In  addition  to  possessing  teeth,  the  wheel 
has  a  series  of  small  holes  all  round  its  edge,  and  in 
any  of  these  a  small  pin  can  be  fixed.  As  a  matter 
of  fact,  in  each  one  two  pins  are  placed,  and  they  are 
so  placed  as  to  correspond  with  the  pauses  in  the 
impulses  sent  out  by  the  corresponding  key. 

To  complete  the  device,  there  is  a  light  catch  which 
is  able  to  lay  hold  of  one  of  these  pins,  and  hold  it 
sufficiently  to  prevent  the  wheel  swinging  back. 

We  now  have  in  our  mind's  eye  a  picture  of  all  the 
important  parts  in  the  selector,  and  can,  in  imagina- 
tion, watch  it  at  work. 

For  this  purpose,  let  us  suppose  that  a  certain 
selector  key  sends  out  the  following  series  of  im- 
pulses :  namely,  4,  6,  7,  and  let  us  watch  these 
impulses  coming  into  a  selector  which  they  are  not 
intended  to  operate. 

The  first  impulse  rotates  the  wheel  to  the  extent 
of  one  tooth,  the  second  pushes  it  a  further  one, 
making  two,  the  next  turns  it  to  three  and  the  next 
to  four  ;  then  the  pause  occurs,  during  which  the  wheel 

227 


TRAFFIC  CONTROL 

slips  back  to  its  starting  point.  Then  the  six  impulses 
follow,  turning  the  wheel  six  teeth,  after  which  it 
slips  back  once  more ;  finally  it  turns  seven  teeth 
before  slipping  back  a  third  time. 

At  the  selector  which  is  set  to  respond  to  that 
particular  signal  the  result  is  quite  different.  The 
four  impulses  come  along  and  act  just  as  they  did  in 
the  former  case,  but  the  fourth  brings  a  pin  into 
engagement  with  the  catch,  and  so  the  wheel  is  held 
throughout  the  pause.  The  six  impulses  then  come 
along  and  carry  the  wheel  round  to  its  tenth  tooth, 
at  which  point  the  second  pin  comes  into  engagement 
with  the  catch,  so  that  the  wheel  is  held  during  the 
second  pause,  after  which  the  seven  impulses  follow, 
carrying  the  wheel  round  to  the  seventeenth  tooth. 

Now  when  the  seventeenth  tooth  is  reached  an 
arm  carried  upon  the  wheel  makes  contact  with  a 
stud  and  rings  a  bell. 

So  whenever  a  key  is  turned  a  series  of  impulses 
goes  forth  to  all  the  selectors.  All  respond,  but  only 
one  is  able  to  reach  the  seventeenth  tooth  and  ring 
the  bell.  All  the  others,  since  their  pins  do  not 
correspond  with  the  pauses,  at  some  time  or  other 
slip  back. 

Usually  there  is  one  key  in  the  controller's  cabinet 
in  which  the  wheel  has  no  discs  alongside  of  it. 
Therefore  it  sends  out  an  uninterrupted  series  of 
seventeen  impulses,  the  result  being  that  that  par- 
ticular key  calls  up  all  the  signal  boxes,  a  useful 
arrangement  when  the  controller  wants  to  send  out 
general  information  of  interest  to  all  the  men. 

The  controller,  therefore,  by  means  of  an  operation 

228  " 


TRAFFIC  CONTROL 

which  takes  up  three  seconds,  can  call  up  any  signal 
box  or  all.  It  is  not  necessary  for  them  to  be  able  to 
ring  him  up  since  he  has  always  got  his  headgear  on, 
so  that  they  only  need  to  speak  and  he  will  hear. 

Should  he  at  any  time  for  a  special  reason  have 
to  take  off  his  headgear  he  can  switch  on  a  loud- 
speaking  telephone,  the  sound  of  which  will  be  loud 
enough  for  him  to  hear  in  any  part  of  the  room. 

It  seems  as  if  it  would  be  impossible  to  improve 
upon  this  system,  so  simple  and  yet  so  effective. 
There  are  but  two  wires,  yet  controller  and  signalmen 
are  so  closely  in  touch  at  every  moment  throughout 
the  day  that  they  might  almost  be  in  the  same  room. 


229 


CHAPTER  XVII 
THE  TUBE  RAILWAY 

ONE  of  the  most  modern  features  in  the  railway 
world  is  the  "  tube  "  form  of  construction  for 
lines  traversing  populous  places. 

Tunnels  are,  of  course,  a  very  old  idea.  Tunnels 
were  made  centuries  ago  to  carry  aqueducts,  and 
later  to  carry  navigation  canals.  Then  followed 
the  railways,  and  tunnels  were  made  all  over  the 
world.  In  most  cases  these  were  through  hills  and 
mountains,  the  heights  of  which  were  too  steep  to 
climb  and  the  bases  of  which  were  too  broad  to  go 
round. 

In  time  there  arose  the  need  for  local  lines  serving 
the  great  towns,  carrying  passengers  in  and  out 
between  the  central  portions  and  the  suburbs,  and 
these  in  many  cases  necessitated  tunnels  in  order 
that  the  town  should  not  be  cut  up  by  the  lines  or 
valuable  sites  of  buildings  destroyed. 

Thus  many  large  cities  have  examples  of  railways 
in  tunnels  just  below  the  surface.  These  generally 
follow  the  line  of  the  public  roads,  and  one  of  the 
great  difficulties  in  their  construction  was  the  diver- 
sion of  the  sewers  and  underground  pipes,  which 
led  to  the  idea  of  boldly  diving  down  below  the  lowest 
of  the  pipes  and  making  the  tunnel  in  virgin  soil, 

230 


THE  TUBE  RAILWAY 

practically  in  a  new  world,  a  world  which  had  not 
(except  at  a  few  isolated  points)  been  penetrated 
since  the  formation  of  the  globe. 

For  this  purpose  there  was  brought  into  play,  in 
a  new  and  improved  form,  a  device  called  a  "  shield." 
It  was  not  a  new  idea,  for  it  had  been  used  by  Brunei 
in  making  the  first  tunnel  under  the  Thames  early 
in  the  nineteenth  century. 

Most  readers  will  at  some  time  or  other  have 
watched  the  family  cook  making  mince  pies,  and  will 
have  seen  her  cutting  out  round  pieces  of  paste  by 
means  of  a  circular  cutter,  consisting  of  a  ring  of  thin 
metal  with  a  sharp  edge  which,  being  pressed  upon 
the  paste,  cuts  a  neat  round  disc. 

Brunei  hit  upon  this  method  for  cutting  a  way 
through  the  London  clay  beneath  the  bed  of  the 
Thames. 

His  shield  was  not  round,  but  square,  but  it  acted 
in  the  manner  of  the  paste  cutter  in  that  it  was 
forced  slowly  forward,  while  men  working  inside  it 
dug  away  the  earth  which  it  enclosed. 

The  modern  tubes  are  circular,  so  that  the  shield 
used  for  them  is  still  more  like  the  cook's  little  cutter. 

Imagine  a  steel  drum  a  dozen  feet  or  so  in  diameter 
and  of  just  about  the  same  proportions  as  the  familiar 
side-drum  of  a  band.  Like  the  side-drum,  too,  it 
has  in  some  cases  two  skins,  but  of  steel  instead  of 
parchment.  The  skins  are  perforated  by  holes  and 
doors  ;  there  are,  moreover,  floors  and  partitions 
between  the  two  "  skins  "  and  in  front  of  the  fore- 
most one. 

Before  the  shield  can  be  brought  into  use,  of 
231 


THE  TUBE  RAILWAY 

course,  a  shaft  has  to  be  sunk  to  the  required  depth 
from  which  the  shield  can  bore  its  way.  This  shaft 
is  dug  out  and  lined  with  a  complete  lining  of  iron, 
formed  of  cast-iron  segments  accurately  fitted  to- 
gether and  connected  by  bolts  and  nuts. 

In  some  cases  the  weight  of  this  lining  has  to  be 
sustained  temporarily  by  rods  from  above  in  order 
that  successive  rings  of  plates  may  be  added  under- 
neath. In  others  the  weight  of  the  lining  is  made 
to  help  with  the  excavation,  a  sharp -edged  ring 
being  placed  at  the  bottom  which  cuts  its  way  down 
as  the  enclosed  earth  is  removed  from  the  inside. 
In  such  a  case  the  rings  are  added  at  the  top  as  the 
whole  thing  descends. 

In  other  cases,  again,  where  water  is  encountered, 
the  upper  end  of  the  shaft  is  covered  in  with  an  air- 
tight cover,  through  which  air  is  forced  by  com- 
pressors in  order  to  keep  the  water  back. 

Where  that  is  done  access  to  the  lower  part  of  the 
shaft  is  through  pairs  of  doors  which  constitute 
"  air-locks." 

Everyone  has  seen  locks  on  a  canal  or  dock,  and 
knows  that  they  consist  of  two  doors  or  pairs  of  doors, 
one  of  which  holds  back  the  water  while  the  other 
is  open,  thereby  allowing  vessels  to  pass  through 
without  letting  through  more  than  a  small  quantity 
of  water.  In  like  manner  does  an  air-lock  work  ;  one 
door  holds  back  the  air  while  a  second  one  is  open, 
so  that  men  and  materials  can  be  passed  through 
without  letting  through  more  than  a  very  small 
quantity  of  air. 

To  pass  through  an  air-lock  from  the  open  air,  a 

232 


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THE  TUBE  RAILWAY 

man  opens  the  first  door,  enters,  closes  the  door 
behind  him  and  then  waits  while  the  air  from  the 
"  pressure  "  side  of  the  lock  is  allowed  to  trickle 
through  and  slowly  raise  the  pressure  between  the 
doors.  When  that  has  been  done  he  opens  the 
second  door  and  passes  through. 

Coming  out,  the  procedure  is  reversed,  the  man 
having  to  wait  in  the  lock  while  the  pressure  is  slowly 
allowed  to  fall  to  that  of  the  atmosphere. 

This  slow  change  of  pressure  is  important  for  the 
health  of  the  men  who  have  to  pass  through  fre- 
quently. With  care,  however,  and  under  reasonable 
pressures,  there  is  nothing  to  fear. 

Readers  may  perhaps  be  tempted  to  wonder  why 
the  change  in  pressure  of  air  should  need  to  be  thus 
gradual.  As  far  as  one  can  see  the  ear-drum  is  the 
only  thing  likely  to  be  much  affected,  but  that  is 
not  so.  There  is  communication  with  the  outer  air 
on  both  sides  of  the  drum  of  the  ear  ;  one  through 
the  outer  ear  and  the  other  through  a  tube  into  the 
mouth  and  so  through  the  nostrils.  If  this  little 
tube,  called  by  doctors  the  "  eustachian  tube,"  be 
for  any  reason  stopped  up,  then  the  air  pressure  will 
increase  on  one  side  of  the  "  tympanum "  faster 
than  on  the  other,  and  a  severe  pain  will  be  felt, 
but  otherwise  the  pressure  changes  equally  on  both 
sides,  and  the  ear-drum  is  in  no  way  affected. 

The  real  trouble  lies  in  the  blood.  Like  all  other 
liquids,  the  blood  is  able  to  absorb  a  certain  amount 
of  gas,  the  amount  depending  upon  the  pressure. 

This  fact  is  the  basis  of  the  manufacture  of  mineral 
waters.  Soda  water  is  simply  water  which  has  been 

233 


THE  TUBE  RAILWAY 

brought  into  contact  with  a  gas  under  pressure.  A 
certain  amount  of  the  gas  is  absorbed,  and  so  long 
as  the  pressure  is  maintained  (as  it  is  so  long  as  the 
stuff  remains  in  the  bottle)  it  looks  just  like  ordinary 
water.  When  you  take  the  cork  out,  however,  the 
pressure  drops,  the  amount  of  gas  which  the  water 
can  hold  drops  too,  and  the  surplus  gas  comes 
bubbling  out.  The  "  fizzy  lemonade,"  beloved  of 
boys,  is  just  the  same  thing  flavoured  with  lemon, 
so  that  the  drink  so  popular  on  a  hot  day  owes  its 
special  feature  to  this  fact. 

Now,  however  good  "  fizzy  "  lemonade  may  be, 
"  fizzy "  blood  is  not  healthy.  Under  pressure, 
the  gases  of  the  atmosphere  are  absorbed  by  the 
blood,  particularly  the  nitrogen,  and  on  the  pressure 
falling  this  bubbles  out,  and  if  that  take  place 
rapidly  certain  blood-vessels  and  parts  of  the  heart 
may  become  clogged,  so  to  speak,  with  nitrogen. 
It  is  only  necessary  to  picture  this  to  realize  that  it 
must  be  very  desirable  to  lower  the  pressure  gradually 
in  order  that  the  liberation  of  the  nitrogen  shall  take 
place  slowly. 

Let  us  assume,  then,  that  the  shaft  is  finished. 
The  next  thing  is  to  determine  the  precise  direction 
which  the  shield  must  follow.  This  is  known,  of 
course,  upon  the  surface,  and  it  is  only  a  question  of 
transferring  that  direction  to  the  bottom  of  the 
shaft. 

This  requires  the  most  scrupulous  care,  because  a 
very  slight  error  to  commence  with  would  result  in 
the  tunnel,  as  it  progressed,  straying  a  long  way  out 
of  its  proper  course.  The  means  employed,  however, 

234 


THE  TUBE  RAILWAY 

is  very  simple.  A  beam  is  laid  across  the  mouth  of 
the  shaft  in  the  precise  direction  which  the  tunnel  is 
to  follow.  Then  two  pieces  of  piano  wire  are  sus- 
pended from  this,  with  heavy  weights  on  their  lower 
ends.  By  sighting  across  these  two  wires  the  engineers 
get  their  starting  direction  at  the  bottom  of  the 
shaft.  After  that  they  have  to  depend  upon  the  use 
of  the  steel  tape  and  the  theodolite. 

Referring  to  the  plan  of  the  route  as  set  out  upon 
the  surface,  the  engineer  knows  that  from  the  start 
the  tunnel  runs  so  far  in  a  perfectly  straight  line, 
then  turns,  let  us  say,  three  degrees  to  the  right. 
The  tunnel  is,  therefore,  made  straight  for  the 
required  distance,  upon  reaching  which  he  sets  up 
his  theodolite  at  the  point  where  the  change  occurs, 
sights  the  telescope  which  forms  a  part  of  the  theodo- 
lite back  upon  his  starting  point,  and  then  turns  it 
"  so  many "  degrees,  which  gives  him  the  new 
direction,  and  so  he  goes  on. 

In  the  same  way  the  engineers  have  to  watch  the 
levels,  for  which  again  the  theodolite  is  employed. 

In  case  there  should  be  any  readers  not  familiar 
with  this  valuable  instrument  it  may  be  well  to 
explain  that  it  consists  of  a  small  telescope  fitted 
upon  a  tripod,  and  combined  with  two  circular  scales 
for  measuring  angles.  Across  the  lens  of  the  tele- 
scope is  a  fine  thread  or  "  wire,"  so  arranged  that 
when  an  observer  looking  through  the  telescope  sees 
a  point  apparently  cut  in  two  by  the  wire  he  knows 
that  the  instrument  is  pointed  directly  at  it. 

If,  then,  he  changes  the  direction  of  the  telescope 
and  points  it  at  something  else,  he  can  read  off,  on 

235 


THE  TUBE  RAILWAY 

one  of  the  scales,  through  how  many  degrees  and 
parts  of  a  degree  he  has  turned  it.  One  scale  shows 
how  far  it  has  turned  in  a  horizontal  plane  and  the 
other  how  far  it  has  turned  in  a  vertical  plane,  so  that 
he  can  measure  the  rise  and  fall  as  well  as  the  deviations 
to  right  and  left. 

This  question  of  rise  and  fall  is  just  as  important 
in  the  case  of  tunnels  as  the  direction  in  a  horizontal 
plane,  for  it  would  evidently  be  as  troublesome  if  a 
tunnel  got  on  to  a  wrong  level  as  it  would  be  if  it 
got  a  wrong  direction. 

It  is  usual  in  most  cases  to  start  at  two  or  more 
shafts  and  work  the  tunnels  until  they  meet,  the 
measurements  being  generally  so  correct  that  an 
error  of  an  inch  or  two  is  regarded  as  quite  large. 

In  one  respect  the  designer  of  a  tube  railway  has 
an  advantage  over  his  colleague  who  has  to  lay  his 
lines  upon  the  surface.  The  latter  is  compelled  to 
a  great  extent  to  follow  the  gradients  of  the  land. 
True,  he  may  make  a  cutting  here  and  an  embank- 
ment there,  but  generally  speaking  he  has  to  follow 
the  lie  of  the  land.  The  "  tube  "  man,  however,  can 
go  up  or  down  just  as  he  likes,  and  he  takes  advantage 
of  this  to  help  the  traffic. 

As  a  train  leaves  a  tube  station  the  line  descends 
so  as  to  help  it  to  accelerate,  in  other  words,  to  get 
up  speed.  Likewise,  the  tube  train  always  approaches 
a  station  uphill,  thereby  saving  brake  power.  The 
two  lines  are  always  in  separate  tunnels,  so  that  to 
each  can  be  given  just  the  right  inclination  at  each 
point.  The  lines  are  not  by  any  means  always  side 
by  side  ;  it  may  happen  that  one  is  above  the  other, 

236 


THE  TUBE  RAILWAY 

even  right  on  top  of  it.  All  these  matters  are  deter- 
mined by  the  circumstances  of  the  particular  case  ; 
they  are  not  done  haphazard,  but  after  the  most 
careful  consideration  of  the  facts. 

But  we  have  been  getting  on  rather  too  fast.  Let 
us  suppose  that  we  have  completed  a  shaft  and 
lowered  the  shield  down  to  the  bottom.  The  iron 
lining  of  the  shaft  will  have  a  circular  opening 
formed  in  it  which  will  in  time  constitute  the  mouth 
of  the  tunnel.  To  this  opening  the  shield  is  carefully 
adjusted,  and  then  tunnelling  operations  proper 
commence. 

The  shield  is  pushed  forward  and  its  sharp  edge 
cuts  into  the  earth,  while  men  passing  through  to 
the  front  commence  to  dig  away  the  earth.  Under 
favourable  conditions  no  air  pressure  is  needed,  but 
generally  it  is  found  useful  to  have  a  little  pressure 
in  order  to  hold  up  the  earth  at  the  "  face,"  or  part 
where  the  men  are  working,  and  to  prevent  it  from 
falling  away  too  readily.  When  that  is  so  an  air-tight 
bulkhead  is  formed  at  some  convenient  point  behind 
the  shield  and  air  is  pumped  in  to  keep  up  the  re- 
quisite pressure. 

In  these  circumstances  the  openings  in  the  dia- 
phragm of  the  shield  can  be  left  open,  and  the  men 
and  materials  pass  freely  through.  Under  less 
favourable  conditions,  however,  when  water  is 
present,  the  doors  in  the  two  diaphragms  of  the 
shield  are  made  to  form  air-locks,  and  a  higher 
pressure  is  maintained  between  the  shield  and  the 
face  than  that  between  the  bulkhead  and  the  shield. 

This  air-pressure  question  is  often  a  very  difficult 

237 


THE  TUBE  RAILWAY 

one,  particularly  when  passing  under  a  river,  because 
the  pressure  sufficient  to  keep  the  water  out  at  the 
bottom  of  the  tunnel  may  be  more  than  is  good  at 
the  top  of  the  tunnel.  If  the  layer  of  earth  above 
the  tunnel  be  thin  the  air  pressure,  if  not  properly 
managed,  may  even  blow  up  the  bed  of  the  river. 
During  the  construction  of  the  Bakerloo  tube  under 
the  Thames  there  was  one  spot  where  air  was  escaping 
up  through  the  river  bed  night  and  day  for  months. 

In  this  case  it  was  possible  to  keep  things  safe  by 
having  the  air-pumps  always  going,  but  in  others 
it  may  be  necessary  to  put  a  patch,  so  to  speak, 
upon  a  weak  spot  in  the  bed  of  the  river,  by  tipping 
boatloads  of  clay  upon  it. 

In  some  cases  the  excavation  is  all  done  by  hand, 
but  in  others  an  "  excavating  shield  "  is  employed. 

In  this  a  huge  wheel  with  scoops  on  its  edge  is 
fixed  to  the  face  of  the  shield  and  driven  round  by 
an  electric  motor.  The  scoops  cut  away  the  earth 
and  then  drop  it  through  shoots  to  the  back  of  the 
shield. 

Another  adjunct  of  the  simple  shield  is  an  arm 
worked  by  hydraulic  power,  which  lays  hold  of  the 
iron  segments  with  which  the  tube  is  lined  and  lifts 
them  into  their  places. 

Furthermore,  to  the  hinder  edge  of  the  shield 
there  are  fixed  a  number  of  hydraulic  rams,  which 
push  against  the  ring  of  segments  last  fixed,  thereby 
propelling  the  shield  along. 

The  joints  between  the  segments  are  made  with 
strips  of  thin  wood,  carefully  impregnated  before- 
hand with  creosote.  These  are  put  in  before  the  rings 

238 


THE  TUBE  RAILWAY 

are  bolted  together,  so  that  when  the  bolts  are 
tightened  up  they  are  gripped  tightly. 

In  the  centre  of  each  segment  there  is  usually 
left  a  hole,  through  which  a  mixture  of  cement  and 
sand  is  squirted  by  means  of  a  compressed  air  squirt, 
commonly  referred  to  by  the  workmen  as  a  "  gun." 
The  mixture  is  made  with  plenty  of  water,  so  that  it 
is  very  fluid,  and  it  fills  up  all  the  little  cavities  left 
between  the  iron  and  the  earth.  This  liquid,  by  the 
way,  is  called  "  grout." 

The  stations  are  enlargements  of  the  ordinary 
tunnels.  They,  too,  are  circular,  and  are  lined  with 
iron  segments.  Usually  they  are  cut  out  by  hand 
after  the  smaller  tunnel  is  made.  The  latter  is  run 
right  through  in  the  first  instance  and  the  enlarge- 
ment made  afterwards.  This  seems  a  waste  of  time 
and  labour,  but  is  found  in  practice  to  be  the  best 
method. 

One  of  the  original  ideas  in  the  construction  of  the 
tubes  was  to  make  them  self-ventilating.  It  is  sur- 
prising how  reluctant  even  a  light  thing  like  air  is 
to  being  pushed  about. 

Anyone  familiar  with  mines  knows  the  huge 
engines  and  fans  which  are  necessary  to  keep  the  air 
moving  in  the  workings,  and  something  of  the  sort 
would  be  necessary  in  the  tubes  but  for  the  action 
of  the  trains  themselves. 

The  train  nearly  fills  the  tube,  so  that  as  it  moves 
along  it  tends  to  push  the  air  along  with  it.  The 
effect  of  this  is  very  noticeable  in  some  of  the 
tubes,  where  the  approach  of  a  train  is  heralded,  a 
long  time  before  it  actually  arrives,  by  the  strong 

239 


THE  TUBE  RAILWAY 

current  of  air  which  it  drives  through  the  tube  and 
often  up  the  shafts  at  the  stations. 

For  a  time  the  earlier  tubes  had  an  earthy  smell, 
which  was  not  pleasant.  They  could  not  get  rid  of 
the  peculiar  atmosphere  which  arises  from  newly 
dug  earth,  but  the  excellent  ventilation  has  by 
now  largely  removed  this,  particularly  where  it  is  re- 
inforced by  the  use  of  artificial  "  ozone,"  as  described 
elsewhere. 

In  thinking  over  the  tubes  and  their  construction 
it  is  impossible  to  avoid  being  struck  by  the  simple, 
common-sense  methods  by  which  they  are  formed. 
It  required,  none  the  less,  great  thought  (not  to  say 
genius)  and  the  most  scrupulous  care,  on  the  part 
of  engineers  and  workmen,  before  they  could  be 
made  with  the  certainty  and  ease  with  which  they 
can  be  made  to-day,  and  we  are  quite  right  in  re- 
garding them  as  one  of  the  wonders  of  our  age. 


240 


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1 


CHAPTER  XVIII 
WONDERS  OF  THE  UNDERGROUND 

THERE  is  not  a  more  remarkable  group  of  rail- 
ways in  the  world  than  those  controlled  by  the 
Underground  Railways  of  London,  Limited. 
Indeed,  it  is  doubtful  if  they  are  equalled. 

The  group  comprises  the  Metropolitan  District 
Railway  and  about  half  a  dozen  "  tubes."  In  addi- 
tion the  company  controls  thousands  of  motor  'buses 
and  miles  of  electric  tramways,  but  we  are  only  con- 
cerned here  with  the  railways. 

The  District  Railway  is  the  one  which  Londoners 
for  many  years  referred  to  as  "  The  Underground." 
One  part  of  it,  together  with  a  part  of  the  Metro- 
politan Railway  and  a  short  piece  of  line  owned 
jointly  by  the  two  companies,  forms  roughly  a  circle, 
and  around  this  trains  run  continually  all  day  long. 
This  route  is  known  as  the  "  Inner  Circle." 

Practically  the  whole  of  the  Inner  Circle  is  under- 
ground, but  it  is  different  from  the  tubes  in  that  the 
tunnels  are  only  just  beneath  the  surface.  They  were 
made  many  years  ago  by  the  simple  method  of  "  cut 
and  cover,"  which  means  that  a  cutting  was  first 
made,  open  to  the  sky,  and  this  was  then  covered 
over  with  a  strong  roofing  of  brick  arch,  upon  the 
Q  241 


WONDERS  OF  THE  UNDERGROUND 

top  of  which  a  roadway  was  laid  or,  in  some  cases, 
buildings  were  erected. 

For  years  it  was  worked  by  steam  locomotives, 
and  while  it  was  very  convenient  in  those  days,  com- 
pared with  the  horse  'buses  above,  the  trains  were  slow 
and  few  compared  with  the  remarkable  services  of 
to-day.  Moreover,  the  smoke  from  the  engines 
caused  the  atmosphere  in  the  tunnels  to  be  very 
unpleasant. 

Starting  from  the  Inner  Circle  are  a  number  of 
branches  to  various  suburbs.  All  of  these  rise  into 
the  open  air  when  they  reach  the  less  crowded  areas. 

The  old  Underground  was  a  fine  piece  of  engineering 
in  its  day,  and  does  honour  to  the  men  who  built  it 
and  worked  it. 

The  next  stage  in  underground  railway  construc- 
tion was  marked  by  the  formation  of  the  City  and 
South  London  Railway,  from  the  Monument,  near 
London  Bridge,  to  Stockwell.  It  was  the  first  of  the 
tubes,  entirely  underground,  at  a  level  sufficiently 
low  to  pass  under  everything  else  ;  it  was  reached  by 
lifts  as  well  as  stairs,  and  its  means  of  ventilation  were 
so  limited  that  before  the  days  of  electric  traction  it 
would  have  been  impossible  to  work  it. 

This,  too,  was  in  its  time  a  great  success,  although 
its  later  imitators  have  improved  upon  many  of  its 
features.  It  was  followed  by  the  Central  London,  also 
a  deep-level  tube,  from  the  Bank  to  Shepherd's  Bush, 
since  extended  in  both  directions.  Later  came  the 
Waterloo  and  City,  the  Baker  Street  and  Waterloo 
(now  known  as  the  Bakerloo),  the  Great  Northern, 
Piccadilly  and  Brompton,  the  City  and  Great  Northern 

242 


WONDERS  OF  THE  UNDERGROUND 

and  the  Hampstead  tube.  All  these  latter  are  deep- 
level  tubes  and  are  very  similar  in  construction  except 
the  Great  Northern  and  City,  which  is  large  enough 
to  take  ordinary  railway  stock. 

It  was  about  half-way  through  this  tube-building 
era  that  a  wonderful  man  from  the  United  States, 
Mr.  C.  J.  Yerkes,  suddenly  burst  upon  the  astonished 
Londoners  with  the  news  that  he  had  in  effect  bought 
the  District  Railway,  never  a  very  prosperous  one 
financially,  and  was  going  to  electrify  it  and  bring  it 
up-to-date.  Later  he  brought  tube  after  tube  under 
the  same  management  until,  now,  the  whole  of  the 
lines  mentioned  except  three  are  grouped  together, 
and  while  to  some  extent  retaining  their  separate 
existence,  are  all  controlled  and  worked  as  one  system 
by  the  Underground  Railways  of  London. 

The  three  exceptions  are  the  Metropolitan,  which 
although  closely  allied  remains  quite  independent, 
the  Great  Northern  and  City,  which  has  been  merged 
into  the  Metropolitan,  and  the  Waterloo  and  City, 
which  belongs  to  the  London  and  South  Western 
Railway  Company. 

The  efforts  of  Mr.  Yerkes  were  crowned  with 
brilliant  success,  from  the  point  of  view  of  the 
traveller,  at  all  events  ;  what  the  financial  result 
has  been  is  not  our  business  here. 

Technically  speaking,  the  chief  points  of  interest 
about  these  lines  are  the  electric  traction,  the  method 
of  constructing  the  tubes  and  the  automatic  signalling, 
but  all  these  things  are  dealt  with  in  other  chapters. 
Here  we  will  consider  some  of  the  other  features 
which  in  one  sense  are  only  minor  ones,  but  which 

243 


WONDERS  OF  THE  UNDERGROUND 


from  the  standpoint  of  the  public  are  of  great  im- 
portance and  which  are  characteristic  of  these  wonder- 
ful lines. 

The  managers  of  the  "  Underground  "  have,  from 
the  very  first,  taken  a  more  sympathetic  attitude 
towards  their  passengers  than  is  customary  on  rail- 
ways. 

It  must  be  confessed,  with  all  due  admiration  for 
those  who  run  railways  in  general,  that  there  is  a 
tendency  with  many  of  them  to  think  that  if  a 
passenger  is  in  any  doubt,  "  well,  he  must  ask  some- 
body." The  Underground  people  try  to  keep  him 
from  ever  being  in  doubt ;  to  make  his  path  so  plain 
and  easy  that  he  can  hardly  go  wrong. 

Let  us  examine  what  may  be  termed  the  out- 
standing example  of  this  :  Suppose  you  go  on  to, 
let  us  say,  the  "  westward-bound  "  platform  at 
Westminster  Bridge  station  on  the  District  line,  and 
we  will  imagine  that  you  want  to  go  to  Baling.  In 
a  most  prominent  position  you  will  see  an  indicator. 
You  can  hardly  fail  to  see  it,  so  well  placed  is  it. 
There  you  will  see  something  like  this  : — 


EALING 
WIMBLEDON       1 
INNER  CIRCLE 

3 
2 

FIG.  18. 

The  names  are  in  bright  white  letters  on  a  blue 
ground  and  the  figures  are  illuminated  by  electric 
lights.  From  this  you  will  notice  that  the  train  you 

244 


WONDERS  OF  THE  UNDERGROUND 

want  will  be  the  third  one  in,  the  first  being 
for  Wimbledon  and  the  second  for  the  Inner 
Circle. 

Presently  a  train  comes  in  and  after  a  short  stop 
passes  out  again.  As  it  leaves  the  station  a  change 
suddenly  comes  over  the  indicator.  The  1  disappears 
from  Wimbledon  and  appears  against  Inner  Circle.  The 
2  disappears  from  Inner  Circle  and  appears  against 
Ealing.  The  3  disappears  from  Baling  and  appears 
against  some  other  route. 

Every  time  a  train  passes  out  of  the  station  that 
happens  ;  the  numbers  changing  so  that  all  through 
the  day  the  next  train,  the  one  after  and  the  one 
after  that  are  indicated  on  the  platform. 

Now  the  remarkable  thing  is  that,  owing  to  the 
signalling  being  automatic,  there  is  no  signalman  to 
operate  this  indicator  at  Westminster  Bridge.  How, 
then,  does  the  indicator  know  what  trains  are  to  be 
expected  and  their  precise  order  ? 

To  answer  this  question  we  need  to  go  back  four 
stations  in  an  easterly  direction,  to  the  Mansion 
House,  where,  owing  to  the  presence  of  sidings,  a 
signalman  is  necessary.  All  the  trains  which  pass 
Westminster  Bridge  in  a  westerly  direction  either 
originate  at  the  Mansion  House  or  else  pass  through 
there. 

Let  us  imagine  that  we  are  in  the  signal  box  at  the 
Mansion  House  station  first  thing  in  the  morning, 
and  that  the  first  train  of  the  day  is  about  to  leave. 
The  signalman,  by  the  movement  of  a  handle  upon 
an  instrument,  sends  a  message  right  along  the  line  to 
every  station  as  far  as  South  Kensington,  where  the 

245 


WONDERS  OF  THE  UNDERGROUND 

next  signal  box  is,  giving  the  destination  of  the  first 
train. 

In  due  course  he  sends  another  and  another.  Each 
train  as  it  leaves  his  station  is  announced  by  him  to  all 
the  others. 

At  each  of  the  other  stations  there  is  an  instrument 
which  is  termed  a  "  magazine,"  a  sort  of  mechanical 
memory,  which  notes  down  these  announcements,  as 
it  were,  for  future  reference.  At  any  moment  the 
magazine  at  one  of  these  stations  knows  what  trains 
have  left  the  Mansion  House  and  in  what  order  they 
have  left. 

The  indicator  at  the  station  is  operated  automatic- 
ally by  each  train  as  it  leaves  the  station,  and  what  it 
does  is  to  publish  the  list  of  the  next  three  trains, 
based  upon  the  information  stored  up  in  the  magazine. 
It  seems  almost  too  human  to  be  possible  in  a  mere 
mechanism,  but  it  is  a  fact,  and  these  instruments 
have  been  working  day  in  and  day  out  for  years  and 
seldom  do  they  make  a  mistake. 

The  indicator  itself  is  a  very  simple  arrangement. 
The  names  of  the  various  routes  are  simply  enamelled 
iron  like  the  familiar  advertisements  to  be  seen  along 
all  railway  lines  and  like  the  street  name-plates  used 
in  many  towns.  Against  the  end  of  each  there  is  a 
piece  of  sheet  metal  with  the  figures  1,  2  and  3  cut 
out  stencil  fashion,  and  behind  each  of  these  figures 
is  an  electric  bulb.  In  the  front  of  the  figures  is  placed 
a  piece  of  frosted  glass,  with  the  result  that  they  are 
invisible  unless  illuminated  by  the  light,  so  that 
by  switching  on  one  of  the  three  lights  one  of  the  three 
figures  can  be  made  visible. 

246 


WONDERS  OF  THE  UNDERGROUND 

The  "  magazine  train  describer,"  or  mechanical 
memory,  is  a  truly  wonderful  instrument.  The  basis 
of  it  is  a  hollow  metal  drum  mounted  upon  a 
spindle.  There  is  also  a  rachet  arrangement  whereby 
it  can  be  turned  round  by  a  series  of  equal  steps. 
This  is  actuated  by  an  electro-magnet  so  that  an 
electric  impulse  can  operate  it. 

The  describer  is  constructed  to  hold  a  record  of 
fifteen  trains,  and  so  the  drum  needs  fifteen  impulses 
to  cause  one  complete  revolution.  At  each  impulse 
it  moves  one-fifteenth  of  a  revolution. 

Across  its  edge  there  are  fifteen  rows  of  small  holes 
(4  in  each),  the  rows  being  equally  spaced  all  round. 
In  each  of  these  holes  there  slides  a  little  iron  peg,  the 
position  of  which  is  normally  such  that  it  projects  on 
the  outside  and  is  flush  on  the  inside. 

Fixed  to  the  stationary  part  of  the  apparatus  is  a 
row  of  little  hammers,  four  in  number,  so  placed  that 
each  one  is  opposite  a  peg.  These  hammers  are 
actuated  by  electro-magnets  so  that  they  can  re- 
spond to  short  currents  of  electricity. 

When  the  signalman  at  the  Mansion  House  wishes 
to  describe  a  train  he  moves  a  pointer  round  a  dial 
until  it  points  at  a  little  tablet  on  which  are  inscribed 
the  words  that  he  wants  to  send.  Then  he  presses  a 
push.  That  sends  current  through  all  the  describers, 
and  in  each  it  actuates  one  or  more  of  the  hammers. 

Let  us  take  the  case  of  that  particular  train  the 
signal  for  which  is  a  current  on  No.  1  line  only.  Then 
all  the  No.  1  hammers  will  act,  will  strike  the  No.  1 
pegs  and  drive  them  in  so  that  they  project  on  the 
inside  of  the  drum. 

247 


WONDERS  OF  THE  UNDERGROUND 

Likewise  if  the  signal  is  No.  2  the  current  will  pass 
along  No.  2  line  and  the  No.  2  hammers  will  act. 
The  same  with  3  and  4  or  any  combination. 

When  the  hammers  have  driven  in  a  peg  or  pegs 
on  each  drum,  the  drums  all  turn  automatically  so 
that  the  next  row  of  pegs  are  presented  to  the  ham- 
mers ready  to  receive  the  next  description. 

Thus  the  drum,  with  some  of  its  pegs  driven  in  and 
some  normal,  constitutes  a  list  of  the  approaching 
trains  and  their  destinations. 

That  brings  us  to  another  part  of  the  mechanism, 
the  purpose  of  which  is  to  read  this  list  and  communi- 
cate it  item  by  item  to  the  indicator  itself. 

The  "  reader,"  as  we  might  call  it,  consists  of  a 
second  drum,  inside  the  first,  with  a  row  of  four  light 
springs  so  placed  that  they  just  touch  the  ends  of  a 
row  of  pegs  when  the  pegs  are  driven  in,  but  not  when 
they  are  normal. 

At  the  commencement  of  the  day,  the  peg  or  pegs 
first  driven  in  make  contact  with  the  springs  and  so  the 
first  train  is  announced.  As  further  signals  come  in 
and  subsequent  rows  of  pegs  are  acted  upon  by  the 
hammers,  so  the  whole  thing  turns  round  step  by 
step,  but  since  the  two  drums  move  together  the 
indicator  still  announces  the  first  train,  for  the  springs 
still  remain  in  contact  with  the  first  row  of  pegs. 

When  a  train  passes,  however,  it  turns  the  inner 
drum  one  step  in  a  backward  direction,  so  that  it  brings 
the  springs  into  contact  with  the  second  row  of  pegs. 

To  put  it  another  way,  the  inner  drum  reads  off 
the  first  item  on  the  list  and  continues  to  do  so,  no 
matter  how  many  items  may  be  added,  until  a  train 

248 


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WONDERS  OF  THE  UNDERGROUND 

turns  it  back  a  step,  after  which  it  reads  off  the  second 
item.  In  due  time  a  second  train  passes,  it  turns  back 
once  more  and  then  reads  off  the  third  item,  and  so  it 
goes  on  throughout  the  day. 

But  the  indicator,  you  will  remember,  shows  three 
trains  and  not  merely  one.  This  is  arranged  for  by 
the  simple  expedient  of  having  three  sets  of  springs, 
the  first  of  which  controls  the  figure  1  on  the  in- 
dicator, the  second  the  figure  2  and  the  third  the 
figure  3. 

There  is  still  one  step,  however,  to  be  explained. 
How  do  the  springs  on  the  inner  drum  know  how  to 
select  that  particular  line  on  the  indicator  where  they 
have  to  exhibit  the  number  ?  In  other  words,  how 
are  they  able  to  translate  the  signal  as  it  is  registered 
upon  the  outer  drum  into  plain  English  ? 

This  is  done  by  a  further  instrument  called  a 
"  combinator,"  which  may  be  described  as  an 
elaborate  form  of  relay  which  is  mentioned  in  another 
chapter.  It  is  so  arranged  that  current  from  No.  1 
spring  completes  a  circuit  and  allows  current  to  flow 
to  a  certain  lamp  in  the  indicator  ;  current  from  No. 
2  sends  it  to  another  lamp  ;  current  from  Nos.  1  and  2 
together  to  a  third,  and  so  on.  Thus  it  translates 
the  signals  recorded  by  the  in-driven  pegs  into 
language  which  the  public  can  understand. 

After  a  row  of  pegs  has  done  its  work  it  passes  a 
row  of  electro-magnets  which  pull  out  any  that  have 
been  driven  in,  and  thus  the  "  slate  is  cleaned,"  ready 
for  a  new  item  to  be  added  to  the  list. 

At  some  stations  there  are  platforms  where  trains  of 
the  same  sort  may  come  in  on  either  side,  and  it  is 

249 


WONDERS  OF  THE  UNDERGROUND 

desirable  to  show  passengers  which  side  to  expect 
the  train  for  which  they  are  waiting. 

In  such  cases  similar  indicators  are  employed, 
except  that  instead  of  the  numbers  there  are  two 
arrows,  one  pointing  to  one  side  of  the  platform  and 
one  to  the  other. 

The  operation  of  these  is  comparatively  simple. 
The  two  arrows  are  cut  out,  like  stencils,  in  an 
opaque  screen  and  illuminated  from  behind  by 
electric  lamps.  When  the  train  is  to  come  on  the 
right-hand  platform  the  signalman  turns  on  the 
lights  on  that  side  and  the  arrow  becomes  visible, 
while  the  arrow  on  the  other  side  remains  invisible 
behind  the  frosted  glass  with  which  both  arrows  are 
covered.  When  he  wishes  to  indicate  the  other 
platform  he  simply  reverses  the  lights. 

Another  feature  of  the  Underground  is  the  moving 
stairways,  or  escalators,  at  some  of  the  stations. 

These  will  no  doubt  be  familiar  objects  to  some 
readers,  but  for  the  benefit  of  others  it  may  be 
explained  that,  when  still,  an  escalator  looks  just 
like  any  ordinary  staircase.  You  can  step  on  at  the 
bottom  and  walk  to  the  top  or  vice  versa,  just  as  you 
do  on  the  stairs  at  home. 

When  at  work,  however,  the  stairs  are  continually 
moving  up  or  down,  as  the  case  may  be,  so  that  you 
need  only  step  on  to  a  stair  and  stand  there  while 
you  are  carried  from  top  to  bottom,  or  from  bottom 
to  top. 

Energetic  people  who  are  in  a  hurry  are  not 
content  to  stand  still  upon  the  stairs  and  let  them  do 
the  work,  but  run  up  or  down  as  if  they  were  ordinary 

250 


WONDERS  OF  THE  UNDERGROUND 

stairs,  thus  adding  their  own  speed  to  that  of  the 
stairs. 

Let  us  take,  in  imagination,  a  trip  on  an  "  up  " 
escalator.  The  first  thing  we  notice  is  a  substantial 
barrier  somewhat  like  a  shop  counter.  From  beneath 
a  strip  of  what  looks  like  floor  is  continually  moving, 
and  on  to  this  "  floor "  we  step.  It  is  moving 
sufficiently  slowly  for  us  to  do  this  with  ease. 

If  we  look  carefully  at  this  piece  of  moving  floor 


oojy 


Fig.  19.— DIAGRAM  SHOWING  HOW  AN  ESCALATOR  WORKS, 

Each  step  is  a  small  trolley  on  four  wheels.  There  are  four 
rails.  The  lower  wheels  run  on  the  inner  rails,  the  upper  ones 
on  the  outer. 

we  notice  that  it  consists  of  long,  narrow  strips 
fitting  closely  together,  and  as  it  approaches  the 
stairs  the  leading  strip  suddenly  commences  to  rise 
and  so  forms  itself  into  a  step.  Strip  after  strip 
thus  rises  in  succession,  including  the  one  we  are 
standing  on,  with  the  result  that  we  are  carried 
upwards  upon  it. 

On  arrival  at  the  top  our  step  ceases  to  rise,  but 
instead  moves  along  horizontally  close  behind  the 
preceding  one,  so  that  once  again  we  find  ourselves 

251 


WONDERS  OF  THE  UNDERGROUND 

standing  upon  a  moving  floor,  off  which  we  step. 
This  moving  floor,  like  that  at  the  bottom,  ends 
underneath  a  strong  barrier,  and  this  is  set  at  an 
incline,  so  that  if  we  failed  to  get  off  we  would  be 
gently  pushed  off. 

As  we  rise  we  probably  lean  against  the  handrail 
at  the  side  of  the  staircase,  and  if  we  are  observant 
we  shall  realize  that  that,  too,  is  moving  at  just  the 
same  speed  as  the  stairs.  It  consists  of  a  strong 
band  of  leather,  or  some  similar  material,  driven  by 
the  same  mechanism  as  the  stairs. 

This  appears  on  the  surface  to  be  very  wonderful, 
but  mechanically  it  is  very  simple,  since  the  stairs 
are  simply  a  train  of  little  four-wheeled  trolleys, 
closely  coupled  together,  passing  round  a  drum  at 
each  end. 

The  front  wheels  and  the  back  wheels  are  not 
quite  the  same  distance  apart,  so  that  they  run  on 
four  rails,  not  on  two.  The  front  pair  of  wheels 
(going  up)  run  on  the  outer  rails  and  the  rear  pair  on 
the  inner  rails. 

On  the  sloping  part  of  the  stairway  all  four  rails 
are  upon  the  same  level,  so  that  in  that  part  of  its 
journey  each  step  travels  just  like  any  ordinary 
four-wheeled  trolley. 

At  the  top  and  the  bottom  the  rails,  of  course, 
turn  into  a  horizontal  plane  so  as  to  carry  the  steps 
along  horizontally,  in  order  that  they  may  form 
that  moving  floor  which  enables  us  easily  to  step  on 
and  off.  If  all  the  four  rails,  however,  were  to  change 
their  direction  at  once,  the  steps  would  tip  over, 
so  the  outer  ones  rise  higher  than  the  inner  before 

252 


WONDERS  OF  THE  UNDERGROUND 

changing,  just  sufficiently  to  keep  each  step  "on  an 
even  keel,"  so  to  speak.  Likewise,  and  for  the  same 
reason,  the  inner  rails  change  direction  at  the  foot 
of  the  stairs  at  a  lower  point  than  do  the  outer  ones. 

All  this  is  rather  difficult  to  explain  in  words,  but 
a  glance  at  the  diagram  on  page  251  will  make  it 
quite  clear. 

But  for  this  arrangement,  of  course,  the  steps 
would  tip  up  when  they  started  to  rise,  a  very  un- 
comfortable thing  for  the  passengers,  but  arranged 
thus  the  steps  always  keep  their  position  and  change 
from  flat  floor  to  stairway  quite  simply  and  auto- 
matically. 

Another  feature  of  the  tubes  which  may  be  men- 
tioned in  conclusion  is  the  supply  of  "  ozone  "  to 
keep  the  air  fresh.  Reference  has  been  made  else- 
where to  the  earthy  smell  prevalent  in  some  tubes, 
and  there  is  no  doubt  that,  in  some  cases  at  all  events, 
the  disappearance  of  this  is  largely  due  to  the  action 
of  "  ozone." 

As  we  all  know,  the  great  purifying  agent  in  all 
things  is  oxygen.  If  we  want  to  clear  away  offensive 
matter  of  any  sort  we  burn  it  if  possible,  which 
means  that  we  rapidly  oxidize  it.  If  it  is  not  possible 
or  convenient  to  burn  it  we  smother  it  with  some 
substance  which  we  call  a  disinfectant,  the  essential 
feature  of  which  is  a  plenteous  supply  of  oxygen. 
All  disinfectants  have  plenty  of  oxygen  in  them  in 
such  a  state  that  it  is  easily  disturbed,  so  that  it 
leaves  the  disinfectant  and  oxidizes  the  offensive 
matter.  This  is  precisely  the  same  thing  as  burning, 
except  that  it  takes  place  more  slowly. 

253 


WONDERS  OF  THE  UNDERGROUND 

Now  ozone  is  simply  oxygen  in  an  unstable  form, 
so  that  it  is  more  ready  to  attack  other  things  than 
ordinary  oxygen  is.  Like  everything  else,  oxygen 
consists  of  atoms,  and  ordinarily  these  atoms  are 
done  up  in  bundles  of  two,  but  in  ozone  they  are  in 
bundles  of  three.  Now  they  do  not  tie  up  nicely  in 
threes  ;  one  of  the  three  is  very  apt  to  slip  out,  and 
so  wherever  there  is  ozone  there  is  likely  to  be  a  lot 
of  loose  atoms  of  oxygen,  under  "which  condition 
they  are  very  active  and  quickly  combine  with 
anything  else  of  a  suitable  kind  that  happens  to  be 
at  hand. 

Ozone  is  usually  supposed  to  be  plentiful  at  the 
seaside,  and  to  it  many  watering-places  owe  their 
invigorating  properties.  It  can  be  made  artificially 
by  means  of  an  electric  discharge,  and  this  is  how  it 
is  provided  for  cleansing  and  purifying  a  tube  tunnel. 
At  certain  places  the  ozone  apparatus  is  installed 
and  the  ozone  produced  is  fanned  through  suitable 
ducts  to  convenient  points,  thereby  giving  to  the 
underground  railway  some  of  the  properties  of  the 
popular  seaside  resort. 


254 


CHAPTER  XIX 

ELECTRIC  TRAINS  AND  HOW  THEY 
ARE  DRIVEN 

THE  steam  locomotive  has  done  grand  service 
to  mankind  in  times  past,  and  its  career  is  by 
no  means  at  an  end,  but  there  can  be  no  doubt 
that  for  certain  types  of  line  dealing  with  certain 
kinds  of  traffic  the  electrically  propelled  vehicle  has 
either  displaced  it  already  or  will  do  so  before  long. 

It  is  a  mistake  which  is  often  made  to  speak  of 
electricity  as  if  it  were  a  source  of  power.  It  is 
nothing  of  the  kind.  It  merely  transmits  power 
from  a  power  house  to  the  trains.  It  does  not  itself 
drive  a  train  any  more  than  the  familiar  leather  belt 
connecting  engine  and  machine  in  a  factory  itself 
drives  the  machine. 

In  the  steam-driven  train  the  engine  is  a  self- 
contained  unit.  It  carries  its  own  coal  and  water  with 
it,  and  only  needs  a  pair  of  rails  to  run  on.  Given 
those  rails  to  run  on  it  can  go  anywhere.  It  may  be 
a  little  costly  to  make,  compared  with  an  electric 
motor,  it  may  not  start  so  readily  as  an  electric  motor, 
it  may  be  less  efficient,  but  it  needs  the  minimum 
of  expenditure  on  the  track. 

The  electric  vehicle,  on  the  other  hand,  is  cleaner, 
handier,  more  easily  driven,  starts  more  quickly  and 

255 


ELECTRIC  TRAINS -HOW  DRIVEN 

is  more  efficient,  but  it  requires  costly  cables  and 
conductor  rails  and  machinery  for  the  transmission 
of  the  power  from  the  power  house  to  the  train. 

These  two  sets  of  facts  lead  to  the  conclusion  that 
for  lines  where  the  trains  are  few  and  the  journeys 
long,  the  steam  locomotive  is  likely  to  hold  its  own 
for  many  years  to  come,  but  that  for  lines  where  the 
trains  are  many  and  the  journeys  short  the  electric 
train  is  pre-eminent. 

The  early  electric  railways  were  modelled  on  the 
street  railway  or  electric  tram.  The  motors  are 
driven  by  current  having  a  force  of  500  volts,  which 
had  become  the  recognized  practice  for  tramways, 
and  the  current  is  of  the  kind  called  direct. 

That  brings  us  to  a  point  which  it  would  be  well 
to  explain  forthwith.  There  are  two  kinds  of  electric 
current.  In  one  the  electricity  flows  steadily  and 
continuously,  always  in  the  same  direction.  This  is 
spoken  of  as  continuous  current  or  direct  current, 
or  more  briefly  as  D.C. 

In  the  other  kind  the  electricity  surges  to  and  fro, 
first  one  way  and  then  the  other.  This  kind  of 
current  is  called  "  alternating,"  or  briefly  A.C.  It 
will  be  noticed  that  A.C.  has  a  property  which  D.C. 
has  not,  namely,  "  periodicity,"  by  which  is  meant 
the  rate  at  which  the  alternations  take  place.  This 
is  generally  fifty  per  second,  but  in  some  cases  less 
and  in  some  more.  It  all  depends  upon  the  con- 
struction and  speed  of  the  dynamo,  so  that  by  making 
the  dynamo  in  a  certain  way  and  driving  it  at  a 
certain  speed  any  desired  periodicity  can  be  ob- 
tained. 

256 


ELECTRIC  TRAINS -HOW  DRIVEN 

The  term  "  cycle  "  is  often  used  in  this  connection 
and  should  perhaps  be  explained.  A  "  cycle  "  of 
operations  is,  of  course,  a  series  of  actions  performed 
over  and  over  again  in  the  same  order.  In  this  case 
current  commences  to  flow  in  a  certain  direction, 
it  grows  until  it  reaches  a  maximum,  then  declines 
and  finally  fades  away  altogether,  then  it  commences 
to  flow  in  the  opposite  direction,  again  attains  a 
maximum,  after  which  it  dies  away  once  more.  That 
is  the  cycle,  and  the  number  of  cycles  per  second 
is  the  periodicity.  So  you  may  read  that  a  certain 
current  is  alternating  and  has  a  periodicity  of  so 
many,  or  it  may  be  described  as  simply  "  alternating 
current,  fifty  cycles,"  or  whatever  the  number 
may  be. 

In  the  case  of  D.C.,  just  as  the  current  is  steady 
so  is  the  pressure  or  "  voltage  "  steady.  In  A.C., 
on  the  other  hand,  the  voltage  varies  just  as  the 
current  does.  If  B.C.,  therefore,  is  said  to  be  250 
volts,  for  example,  it  remains  steadily  at  about  that 
pressure  all  the  time.  If  the  same  is  said  of  A.C., 
however,  it  means  that  that  is  an  average  pressure, 
and  that  sometimes  it  is  much  higher.  This  has  to 
be  borne  in  mind  when  matters  of  insulation  are 
under  consideration. 

This  preliminary  explanation  is  necessary  in  order 
to  lead  up  to  the  fact  that  there  are  two  distinct 
types  of  electrically  propelled  railway.  The  first  is 
worked  by  direct  current,  and  of  this  the  Underground 
Electric  Railways  of  London  may  be  taken  as  a 
great  example.  In  the  other  type  alternating  current 
transmits  the  power  to  the  trains,  and  of  this  what  is 

R  257 


ELECTRIC  TRAINS -HOW  DRIVEN 

called  the  "  Overhead  Electric  "  line  of  the  London 
and  Brighton  and  South  Coast  Railway,  serving 
some  of  the  southern  suburbs  of  London,  may  be 
taken  as  typical. 

It  may  seem  at  first  sight  that  since  both  are 
electric  they  must  be  similar,  but,  in  fact,  they  are 
very  different.  The  motors  are  different,  the  methods 
of  carrying  the  power  to  the  train  are  different,  and 
the  fitting  up  of  the  trains  themselves  is  different. 
It  will  therefore  be  necessary  to  describe  them 
separately. 

We  will  commence  with  the  D.C.  kind.  The 
starting  point  is  the  generating  station,  where  the 
power  is  obtained  from  fuel  of  some  sort,  or  from 
falling  water,  if  that  is  available. 

Here  are  a  number  of  generators  or  dynamos, 
each  driven  by  an  engine  or  a  steam  turbine  or  a 
water  turbine.  Whatever  the  source  of  power  may 
be  it  is  employed  in  the  most  economical  manner. 
One  of  the  reasons  for  the  economy  of  the  electrical 
system  as  compared  with  the  steam  is  that  in  a  well- 
equipped  generating  station  the  fuel  can  be  burned 
to  much  better  advantage  than  is  possible  in  an 
engine  wrhich  has  to  be  run  with  the  train. 

It  is  possible  to  reckon  that  quantity  of  work 
which  is  the  precise  equivalent  of  the  heat  from  the 
fuel.  By  burning  a  sample  of  the  latter  the  number 
of  heat  units  per  pound  of  coal  can  be  ascertained, 
and  each  unit  under  ideal  conditions  would  do  work 
equal  to  raising  773  Ibs.  a  foot  high,  or  773  foot- 
pounds. 

Unfortunately,  in  the  conditions  under  which  we 


ELECTRIC  TRAINS— HOW  DRIVEN 

live,  this  result  is  quite  impossible,  but  this  figure 
furnishes  us  with  a  standard  by  which  we  can  com- 
pare the  "  efficiency  "  of  power  plants  of  various 
kinds.  If,  for  instance,  it  is  found  that  77  foot-pounds 
of  work  are  done  for  every  heat  unit  in  the  fuel 
burnt,  then  that  plant  is  said  to  have  an  efficiency  of 
ten  per  cent. 

Now  if  the  efficiency  of  a  steam  locomotive  were 
five  per  cent  it  would  be  extremely  good.  Many  are 
far  less  than  that,  whereas  in  a  power  house  the 
efficiency  would  run  into  possibly  the  twenties. 

In  some  power  stations  internal-combustion  engines 
are  used,  because  with  them  a  higher  efficiency  is 
possible  than  with  any  form  of  steam  engine.  They 
suffer,  however,  from  certain  defects,  the  result  of 
which  is  that  in  the  largest  stations  steam  is  mostly 
to  be  found,  more  especially  steam  turbines.  In  the 
steam-driven  power  house  much  of  the  work  is 
automatic.  At  the  great  generating  station  of  the 
London  Underground  Railways  at  Chelsea  the 
boilers  are  on  the  upper  floors  of  the  boiler  house. 
The  coal,  having  been  elevated  mechanically  to  the 
level  of  the  roof,  runs  along  a  conveyor  right  up  in 
the  apex  of  the  roof,  whence  it  is  thrown  off,  again 
automatically,  into  bunkers.  From  these  it  falls 
into  the  mechanical  stokers,  which  continually  feed 
it  into  the  furnaces  of  the  boilers.  The  ash,  in  like 
manner,  falls  down  shoots  to  a  lower  floor,  whence 
it  is  carried  out  by  mechanical  means. 

For  the  sake  of  economy  several  devices  are 
employed  in  the  stationary  power  house  which  are 
quite  impossible,  or  only  partly  possible,  on  the 

259 


ELECTRIC  TRAINS -HOW  DRIVEN 

locomotive.  For  one  thing,  the  heat  which  would 
otherwise  escape  up  the  chimney  is  made  to  pass 
through  ranges  of  pipes,  forming  what  are  called 
"  super-heaters,"  whereby  some  of  it  is  captured  and 
used  to  raise  the  temperature  of  the  steam.  Later 
on  more  heat  is  extracted  from  the  waste  gases  on 
their  way  to  the  chimney  by  ranges  of  pipes  called 
"  economisers,"  in  which  heat  that  would  otherwise 
be  wasted  is  used  to  heat  the  water  on  its  way  to  the 
boilers. 

The  engines,  too,  whether  turbine  or  reciprocating, 
are  fitted  with  "  condensers,"  cool  chambers  into 
which  the  steam  passes  after  leaving  the  engine.  In 
the  condensers  the  steam,  being  cooled,  collapses 
into  water,  so  that  inside  the  condenser  there  is 
always  a  fairly  good  vacuum,  and  the  suction  of  the 
vacuum  pulling  upon  the  engine  is  added  to  the 
pressure  of  the  steam  pushing  at  the  other  side. 

The  keeping  cool  of  the  condensers  is  quite  a  big 
business  at  a  large  plant,  necessitating  vast  quantities 
of  cold  water.  If  a  large  river  or  lake  be  handy, 
this  is  simply  a  question  of  pumping,  but  otherwise 
some  kind  of  cooling  scheme  is  needed.  At  some 
stations  they  carry  the  heated  water  to  the  top  of  a 
huge  tower  and  let  it  fall,  like  rain,  the  contact  with 
the  air  causing  it  to  cool  rapidly.  In  other  places  it 
is  sprayed  upwards  in  a  very  fine  spray  with  the  same 
result. 

All  these  devices,  super-heaters,  economizers,  con- 
densers, cooling  devices  and  the  rest  are  all  intended 
for  one  purpose,  namely,  to  obtain  the  best  possible 
result  in  work  from  the  heat  derived  from  the  fuel. 

260 


ELECTRIC  TRAINS -HOW  DRIVEN 

These  waste-saving  appliances  are,  of  course, 
impossible  to  any  considerable  extent  on  the  loco- 
motive. 

As  a  rule,  each  generator  has  a  separate  engine 
or  turbine  to  drive  it,  so  that  the  two  form  a  unit. 
The  current  from  each  unit  is  led  by  cables  to  the 
switch  board,  a  large  structure  for  holding  the 
switches  and  measuring  instruments,  by  means  of 
which  the  flow  of  current  is  controlled. 

Behind  the  "  board  "  there  are  usually  a  number  of 
horizontal  bars  of  copper,  called  "  bus  bars,"  to 
which  the  current  from  all  the  generators  is  led  and 
from  which  all  the  outgoing  cables  draw  the  current, 
which  they  lead  away  to  the  distant  parts  of  the 
line. 

From  the  very  nature  of  a  railway  it  follows  that, 
no  matter  how  nearly  central  the  power  station  may 
be,  some  of  the  current  will  have  to  travel  a  great 
distance  ;  in  other  words,  long  cables  will  be  required 
to  carry  it  to  distant  parts  of  the  line.  Practically, 
the  only  material  for  these  is  copper,  and  copper  is 
expensive.  Hence  it  is  of  the  utmost  importance 
that  these  cables  should  be  as  thin  as  possible,  or 
the  cost  in  copper  will  be  enormous. 

Let  us  take  an  example.  If  we  think  for  a  moment 
of  the  problem  of  sending  power  by  water  through  a 
pipe  we  can  see  that  it  is  equally  possible  to  achieve 
our  end  by  sending  a  lot  of  water  through,  with  only 
a  little  force  behind  it,  or  a  little  water  with  a  lot 
of  force.  The  chief  difference  between  the  two  is 
that  the  former  requires  a  much  bigger  pipe  than  the 
latter. 

261 


ELECTRIC  TRAINS -HOW  DRIVEN 

Although  we  cannot  picture  it  to  ourselves  so 
easily  the  transmission  of  power  by  electricity  is 
very  similar.  To  attain  a  given  result  the  less 
pressure  we  use  the  more  current  do  we  need,  and  the 
larger  the  cables  necessary  to  carry  it.  On  the 
other  hand,  by  using  a  high  pressure  we  can  reduce 
the  quantity  of  current  and  so  bring  down  the  expense 
for  copper  to  a  minimum. 

It  is  therefore  an  invariable  rule  that  the  generators 
in  the  central  power  house  are  so  constructed  as  to 
give  out  a  comparatively  small  current  at  a  very 
high  pressure,  or,  to  use  the  more  frequent  term, 
"  tension." 

This  pressure  or  tension  is  that  quantity  which 
is  expressed  in  "  volts."  The  current  for  the  Under- 
ground is  generated  at  11,000  volts. 

All  mechanically  generated  current  is  of  the 
alternating  variety.  A  few  attempts  have  been  made 
to  devise  machines  to  generate  direct  current,  but 
none  has  been  satisfactory.  In  order  to  obtain 
direct  current,  therefore,  the  generator  has  to  be 
fitted  with  a  part  called  a  commutator,  a  mechanical 
device,  the  effect  of  which  is  to  change  the  direction 
of  the  current  passing  through  it  at  frequent  in- 
tervals. The  effect  of  this  is  to  neutralize  the  original 
alternations.  It  is  as  if  the  commutator  took  one- 
half  of  each  cycle  and  reversed  it,  thereby  changing 
the  alternating  current  into  direct. 

Now  this  device  does  not  act  nicely  when  the 
voltage  is  high,  so  that  the  high-tension  currents 
which  leave  the  central  station  to  carry  the  power 
far  and  wide  are  always  generated  by  alternating 

262 


ELECTRIC  TRAINS -HOW  DRIVEN 

current  generators,  or,  as  they  are  more  frequently 
termed,  alternators. 

So  the  high-tension  alternating  current  sets  out 
upon  its  journey.  Dotted  about  the  railway  system 
are  smaller  stations,  known  as  sub-stations,  where 
the  current  is  transformed  and  converted  in  order 
to  make  it  suitable  for  driving  the  motors  on  the 
trains. 

The  use  of  these  two  terms  is  quite  arbitrary.  So 
far  as  their  real  meaning  is  concerned  either  of  them 
could  be  used  instead  of  the  other,  but  it  is  the 
custom  to  speak  of  transforming  the  current  from 
high  tension  to  low  and  converting  it  from  alternating 
to  direct. 

The  transformers  in  the  sub-stations  are  in  prin- 
ciple precisely  like  the  induction  coils  with  which 
most  of  us  have  at  some  time  or  other  tried  to  shock 
people.  Of  course,  they  are  much  larger,  but  like 
the  induction  coil  they  consist  of  two  coils  of  insulated 
wire.  Through  the  first  is  passed  the  high-tension 
current  from  the  power  station,  and  that,  being 
alternating,  acts  upon  the  other  coil,  and  the  two 
are  so  arranged  that  the  secondary  current  is  some- 
where about  the  500  volts  required  by  the  motors. 

It  would  be  possible  to  use  this  transformed 
current  straight  away  ;  but  the  direct  current  motor 
is  such  a  beautiful  machine,  it  starts  so  nicely  and 
is  so  easily  controlled  that  many  engineers  prefer  to 
convert  this  low-tension  current  into  direct  current 
before  sending  it  out  to  the  conductor  rails  for  use 
by  the  trains. 

Therefore  the  sub-station  also  contains,  in  addition 

263 


ELECTRIC  TRAINS— HOW  DRIVEN 

to  the  transformers,  machines  called  converters. 
These  are  in  appearance,  and  in  construction,  too, 
very  like  generators,  but  they  are  not  driven  mechani- 
cally. The  alternating  current  which  is  fed  into 
them  serves  to  drive  them,  and  in  passing  through 
them  is  changed  into  direct  current  by  a  commu- 
tator, such  as  has  already  been  described. 

The  total  result  is,  then,  that  alternating  current 
at  11,000  volts  or  thereabouts  goes  into  the  sub- 
station, while  direct  current  at  about  500  volts 
comes  out. 

The  cables  or. "feeders"  from  the  sub-stations 
terminate  at  various  points  upon  the  conductor 
rails,  which  are  laid  down  by  the  side  of  the  rails 
upon  which  the  trains  run  and  from  which  the  trains 
pick  up  the  current  as  they  go. 

Upon  the  trains  themselves  the  only  apparatus 
necessary  is  one  or  more  motors  and  a  controller, 
by  means  of  which  the  driver  can  regulate  the  speed 
and  the  direction  of  the  trains. 

The  controller  generally  has  two  handles.  One  of 
these  determines  the  direction.  An  electric  motor 
consists  of  two  sets  of  electro-magnets,  which  act 
upon  each  other.  If  you  change  the  direction  of  the 
current  in  one  of  them  you  reverse  the  action.  Hence 
all  that  this  handle  has  to  do  when  it  is  turned  is 
to  change  the  direction  of  the  current  through  one 
of  the  sets  of  magnets  in  the  motors.  This  it  does 
in  a  very  simple  manner.  There  is  inside  the  con- 
troller a  drum-shaped  object  carrying  a  number  of 
curved  metal  strips,  carefully  insulated  from  each 
other  and  from  the  drum.  On  the  frame  of  the 

264 


ELECTRIC  TRAINS -HOW  DRIVEN 

controller  there  are  fingers  of  metal,  which  in  certain 
positions  make  contact  with  the  strips.  The  handle 
is  attached  to  the  end  of  the  shaft  upon  which  the 
drum  is  fixed,  and  when  it  is  moved  it  takes  certain 
strips  out  of  contact  and  brings  others  into  contact, 
thus,  in  the  simplest  imaginable  way,  making 
the  necessary  changes  in  the  direction  of  the 
current. 

The  other  handle  controls  the  speed.  It  likewise 
is  connected  to  a  drum  carrying  strips,  and  as  it  is 
turned  it  varies  the  connections  with  the  corre- 
sponding fingers.  If  a  slow  speed  is  required  it 
sends  the  current  round  through  a  lot  of  coils  of 
wire,  the  resistance  of  which  diminishes  the  quantity 
of  current  and  so  keeps  the  speed  down.  When  it 
is  desired  to  increase  the  speed  the  controller  cuts 
out  these  resistance  coils  one  by  one  until,  at  the 
highest  speed,  the  current  is  going  straight  to  the 
motors  without  the  intervention  of  any  resistance 
at  all. 

Since  the  driver  of  an  electric  train  is  frequently 
alone  in  his  cabin  and  has  no  mate,  as  his  colleague 
of  the  steam  train  has,  the  controller  handle  is  made, 
when  left  alone,  to  spring  back  to  the  position  where 
it  cuts  off  all  current  and  stops  the  train.  This 
device,  which  is  nicknamed  by  the  men  the  "  dead 
man's  handle,"  is  intended  as  a  safeguard  against 
the  possibility  of  a  driver  fainting  at  his  post  and  the 
train  running  along  out  of  control. 

The  brakes  on  an  electric  train  are  generally 
worked  by  compressed  air,  in  a  similar  manner 
to  those  on  many  steam  trains.  There  is  a  small 

265 


ELECTRIC  TRAINS— HOW  DRIVEN 

subsidiary  motor,  the  duty  of  which  is  to  keep  the 
reservoir  of  compressed  air  filled. 

Now  let  us  turn  our  attention  to  the  alternating 
current  systems  and  see  how  they  differ  from  those 
just  described. 

The  power  station  is  not  materially  different,  but 
of  sub-stations  there  are  none.  Therein  lies  the 
first  difference. 

The  high-tension  alternating  current  is  fed  straight 
to  the  conductors  from  which  the  trains  collect  it. 
Since  the  tension,  or  pressure,  is  so  high,  to  touch 
one  of  these  conductors  would  mean  instant  death, 
so  a  rail  upon  the  ground,  on  to  which  an  unwary 
platelayer  might  step,  is  out  of  the  question.  In- 
stead of  a  conductor  rail,  therefore,  there  is  a  heavy 
copper  wire,  supported  high  in  air  out  of  everyone's 
reach.  Not  only  does  it  need  to  be  high  up,  but  the 
insulation  has  to  be  exceedingly  good,  for  otherwise 
the  current  would  leak  to  the  posts.  Moreover, 
the  conductor  wire  has  to  be  very  level,  for  if  it  rose 
and  fell  to  any  great  extent  the  collector  on  the  top 
of  the  train  would  not  make  a  steady  contact  with  it. 
Long  spans  of  wire,  such  as  we  see  in  the  case  of 
tramways,  are  all  right  for  the  comparatively  slow- 
moving  cars,  but  they  would  never  do  for  the  more 
speedy  train. 

These  two  last  difficulties,  the  insulation  and  the 
level  wire,  are  overcome  by  one  and  the  same  ar- 
rangement. 

Tall  posts  or  light  steel  towers  are  erected  by  the 
side  of  the  line,  generally  in  pairs  with  a  light  steel 
girder  spanning  between  them,  like  a  bridge.  To  these 

266 


ELECTRIC  TRAINS -HOW  DRIVEN 

there  are  fixed  two  steel  wires  which,  not  being  very 
tightly  stretched,  form  easy  curves.  Below  these 
wires  and  between  them  is  stretched  the  conductor, 
supported  from  them  by  short  wires  at  frequent 
intervals.  By  varying  the  length  of  these  short 
wires  it  is  thus  possible  to  keep  the  conductor  prac- 
tically straight. 

One  may  wonder,  perhaps,  why  the  conductor 
should  not  be  pulled  so  tightly  between  its  supports 
that  it  would  be  practically  level  all  along,  but  the 
answer  is  that  to  do  so  would  need  such  a  tremendous 
pull  as  almost,  if  not  quite,  to  break  it.  This  does 
not  happen,  however,  when  the  wire  can  be  sup- 
ported at  frequent  intervals  as  it  is  by  the  short 
wires. 

It  may  be  asked,  does  not  the  same  thing  apply  to 
the  two  steel  wires.  It  does,  but  they  are  not  pulled 
tight,  being  left  fairly  loose,  since  a  considerable 
sag  in  them  does  not  matter.  It  is  all  taken  up  by 
the  variation  in  the  length  of  the  short  wires. 

The  steel  wires  are  carried  on  insulators  fixed 
upon  the  bridges.  This  is  theoretically  unnecessary, 
because  there  ought  to  be  no  current  in  the  steel 
wires  at  all.  This  is  so,  because  near  the  centre  of 
each  of  the  short  wires,  or  where  it  connects  to  the 
long  steel  wires,  there  is  inserted  a  porcelain  insulator. 
In  other  words,  every  short  wire  is  itself  insulated. 

If  everything  were  as  it  ought  to  be  no  current 
should  get  to  the  steel  wires,  but  should  it  by  any 
chance  do  so  the  other  insulators,  those  mentioned 
first,  come  into  operation  and  prevent  the  current 
from  escaping  further. 

267 


ELECTRIC  TRAINS -HOW  DRIVEN 

In  fact,  they  act  together,  reinforcing  each  other 
and  so  making  the  whole  arrangement  very  safe. 

On  the  top  of  each  motor  coach  in  the  trains  there 
is  a  collector.  It  is  rather  different  from  the  simple 
arm  with  a  wheel  at  the  end,  such  as  tramway  cars 
have,  although  the  purpose  is  much  the  same.  Here, 
again,  the  difference  is  made  necessary  by  the  higher 
speed  of  the  train. 

In  this  case  the  collector  is  usually  a  frame  or 
metal  rectangle,  one  side  of  which  is  hinged  to  the 
top  of  the  coach,  while  the  whole  thing  is  raised  up 
so  that  the  opposite  side  presses  steadily  upwards 
against  the  underside  of  the  conductor  wire.  In 
practice  it  is  desirable  that  the  collector  should  trail 
along  rather  than  be  pushed  along  in  contact  with 
the  wire,  hence  each  motor  coach  has  two,  one  each 
way,  and  when  the  train  reverses  one  goes  out  of 
action,  lies  flat  upon  the  roof  so  as  to  be  out  of 
action,  while  the  other  one  is  raised  and  comes  into 
operation.  The  change  is  made  quite  easily  by 
compressed  air  worked  from  the  driver's  cabin. 

On  arrival  upon  the  train  the  current  is  still  at  a 
very  high  voltage,  too  high  for  practicable  use  on 
the  motors,  so  it  is  led  to  a  transformer  carried  upon 
the  train  which  lowers  the  voltage,  and  the  low-tension 
current  is  then  led  to  the  motors. 

One  drawback,  as  will  be  noticed,  to  this  system 
is  that  it  entails  the  constant  hauling  about  of  heavy 
transformers.  Another  very  obvious  one  is  the 
high  cost  of  the  structures  for  carrying  the  con- 
ductors. 

Which  is  really  the  better  of  the  two  is  a  matter  of 
268 


ELECTRIC  TRAINS -HOW  DRIVEN 

much  discussion.  Like  most  questions,  there  is 
much  to  be  said  on  both  sides,  and  it  seems  highly 
probable  that  the  next  step  will  be  a  compromise 
between  the  two  ;  that  is  to  say,  high-tension  current, 
transformed  down  by  transformers  dotted  about  the 
system  and  fed  to  conductor  rails  upon  the  ground. 

In  some  installations  there  are  two  separate  con- 
ductor rails,  one  positive  and  one  negative,  or  in  other 
words,  one  along  which  current  flows  from  the  power 
station  and  one  along  which  it  travels  back  again. 
There  are  others,  however,  in  which  only  one  is 
used,  the  track  rails  serving  the  purpose  of  the  other. 

It  may  be  asked,  "  What  is  the  good  of  the  negative 
or  return  rail  ?  Is  it  so  that  the  electricity  can  be 
used  over  again  ?  If  it  is  not  used,  is  the  electricity 
wasted  ?  " 

The  answer  is  that  when  heavy  currents  are  let 
loose,  so  to  speak,  in  an  uninsulated  rail,  they  are 
apt  to  stray  about  and  cause  corrosion  of  pipes  and 
other  things  buried  in  the  ground  by  setting  up  the 
action  called  "  electrolysis."  Consequently,  where 
the  flow  of  current  is  likely  to  be  heavy  and  there 
are  many  pipes  about  the  insulated  return  is  generally 
installed.  Where  the  currents  are  not  so  heavy, 
because  there  are  fewer  trains  and  the  line  runs 
through  more  open  country,  the  insulated  return  is 
often  dispensed  with. 

The  question  of  wasting  electricity  does  not  really 
arise  at  all,  because  the  whole  earth  is  saturated  with 
it,  and  consequently  it  is  about  the  cheapest  thing  in 
existence.  It  only  becomes  of  value  when  force  is 
put  into  it.  It  is  the  force  which  costs  money,  and 

269 


ELECTRIC  TRAINS— HOW  DRIVEN 

the  force  which  makes  an  electric  current  valuable. 
Now  this  force  is  used  up  in  the  motors.  The  very 
essence  of  an  electric  motor  is  that  it  catches,  so  to 
speak,  the  force  in  the  current,  extracts  it  and  uses 
it  for  some  mechanical  purpose,  in  this  case  to  drive 
the  train. 

That  is  the  reason  why  there  is  no  danger  in  using 
the  rails  of  a  tramway  in  the  public  street  for  the 
return  current.  By  the  time  the  current  has  been 
through  the  motors  all  its  force  is  gone,  there  is 
barely  enough  left  to  ring  an  electric  bell,  and  cer- 
tainly not  enough  for  anyone  to  feel. 

So  that  is  how  electric  trains  are  driven.  No 
attempt  has  been  made  to  describe  all  the  slight 
differences  which  occur  between  different  systems, 
but  enough  has  been  said  to  give  a  general  idea  of 
the  broad  principles  underlying  them  all,  and  the 
facts  stated  will  enable  anyone  to  understand  generally 
how  they  work. 


270 


CHAPTER  XX 
A  RAILWAY  IN  THE  AIR 

IF  you  sail  in  a  ship  across  the  Atlantic  as  if 
you  were  going  through  the  Panama  Canal,  but 
instead  of  entering  the  canal  turn  to  the  left 
and  follow  the  coast  for  a  while,  you  will  come  to  a 
large  river  called  the  Magdalena. 

This  rises  in  the  Andes,  flows  down  a  broad  valley 
formed  by  two  spurs  of  that  great  range,  and  serves 
as  an  important  highway  for  traffic.  The  country 
through  which  it  passes  is  the  Republic  of  Colombia, 
and  one  of  the  most  important  towns  upon  its  banks 
is  called  by  the  beautiful  name  of  Mariquita. 

Away  to  the  westward  of  Mariquita  is  a  stretch  of 
country  of  the  most  varied  types.  Parts  of  it  are 
tropical,  with  the  luxuriant  vegetation  which  usually 
grows  under  those  conditions.  Other  parts  are  rocky 
and  precipitous,  as  we  might  expect  when  we  remem- 
ber the  nearness  of  the  great  Andes  range.  Some  of 
the  higher  valleys,  again,  are  of  great  fertility, 
sharing  as  they  do  many  of  the  advantages  of  the 
tropical  sun,  but  escaping  many  of  the  disadvantages 
because  of  their  altitude. 

Particularly  is  this  the  case  with  an  area  the  centre 
of  which  is  the  town  of  Manizales,  about  forty-five 
miles  to  the  westward  of  Mariquita.  This  district 

271 


A  RAILWAY  IN  THE  AIR 

produces  bountiful  crops  of  coffee  and  spices,  but 
unfortunately  a  range  of  high  mountains  with  rugged 
foot-hills  intervenes  between  the  two  towns,  so  that 
Manizales  must  be  one  of  the  most  isolated  places 
for  its  size  in  the  whole  world. 

Although  it  has  a  population  of  about  30,000  it 
has  no  main  road  leading  to  anywhere.  The  longest 
road  out  of  it  is  only  a  few  miles  long  and  it  leads  to 
nowhere,  but  simply  ends  by  losing  itself  among  the 
rough  country  at  the  foot  of  the  mountains. 

Given  a  reasonably  good  path,  there  is  many  a 
man  who  could  walk  the  distance  betwreen  these  two 
towns  in  a  day,  but  until  a  few  years  ago  the  only 
communication  between  the  two  was  a  mule  journey 
of  about  three  days  in  summer  and  possibly  nine  or 
ten  in  the  winter. 

Not  only  was  much  time  thus  lost,  but  much 
valuable  merchandise  was  spoilt  by  damp  and  heat 
experienced  during  the  trip.  In  short,  the  whole  of 
this  district,  rich  in  its  crops,  round  Manizales,  was 
rendered  poor  because  it  had  no  satisfactory  outlet 
through  which  it  could  exchange  its  wealth  with 
other  people. 

At  Mariquita  there  is  a  railway,  owned  by  an 
English  company,  called  the  Dorada  Railway  Com- 
pany, who  had  for  years  looked  towards  Manizales 
and  coveted  the  valuable  traffic  which  was  waiting 
to  be  carried,  if  only  they  could  devise  a  practicable 
way. 

The  nature  of  the  country,  however,  put  an 
ordinary  railway  quite  out  of  the  question.  To 
commence  with,  the  steepness  of  the  gradients  would 

272 


A  RAILWAY  IN  THE  Affi 

be  far  too  great.  The  town  of  Mariquita  is  only 
1500  ft.  above  the  sea,  but  Manizales  is  about  7000, 
and  between  them  is  the  mountain  range,  at  least 
12,000  ft.  high.  In  addition  to  this  the  roughness 
of  the  country  in  parts  would  necessitate  such  a 
series  of  bridges  and  tunnels  and  cuttings  and  via- 
ducts that  the  cost  would  be  prohibitive.  No  amount 
of  traffic  could  ever  pay  a  dividend  upon  it. 

All  these  difficulties,  however,  vanish,  or  at  any 
rate  are  greatly  reduced,  if  the  railway  can  be  lifted 
off  the  ground  and  carried  through  the  air,  which  is 
practically  what  has  been  done.  A  rope  railway,  or 
ropeway,  has  been  installed,  whereby  the  loads  of 
goods  are  carried  easily  and  economically  over  the 
wildest  mountainous  country. 

It  is  not  suggested  that  the  idea  of  a  ropeway  was 
invented  for  this  particular  work.  The  principle  is 
much  older  than  that  and  there  are  many  such 
things  about,  but  this  was  the  first  time  on  which 
it  had  been  used  on  so  large  a  scale  and  as  a  definite 
extension  of  a  railway.  This  is  emphasized  by  the 
fact  that  a  new  company  was  formed  in  London, 
called  the  Dorada  Railway  Ropeway  Extension 
Company,  Limited,  to  carry  it  through. 

The  earliest  ropeways  consisted  of  two  ropes, 
parallel  with  each  other,  securely  held  at  each  end, 
along  which  little  trolleys  were  hauled  by  means  of 
a  third,  endless,  rope  to  which  the  trolleys  were 
attached.  Buckets  or  some  other  convenient  form 
of  receptacle  were  hung  beneath  each  trolley,  and 
there  was  an  arrangement  whereby  the  trolleys  on 
reaching  their  destination  could  be  detached  from 
s  273 


A  RAILWAY  IN  THE  AIR 

the  "  hauling  rope  "  and  run  on  to  a  sort  of  siding  or 
"  shunt  rail,"  as  it  is  termed,  to  be  unloaded. 

If  the  length  of  the  ropeway  is  very  short  the 
"  track  ropes  "  need  only  to  be  strongly  held  at  each 
end,  but  in  the  great  majority  of  cases  intermediate 
supports  are  required  in  the  form  of  towers  or  trestles. 
Each  trestle  has  two  projecting  arms  near  its  top, 
so  that  it  may  be  likened  to  a  man  of  gigantic  pro- 
portions standing  between  the  ropes  with  outstretched 
arms,  supporting  one  rope  in  each  hand.  The  track 
ropes  are  so  attached  to  these  "  arms  "  that  the 
wheels  of  the  trolleys  can  run  easily  past  them. 

The  heights  of  the  trestles  vary  according  to  cir- 
cumstances. In  some  cases  they  only  need  to  be  just 
high  enough  to  allow  the  buckets  to  clear  the  ground. 
Such  an  instance  would  occur  at  the  top  of  a  hill. 
At  the  bottom  of  a  deep  valley,  however,  if  the 
trestle  were  equally  short,  the  ropes  might  be  far 
too  steep,  and  to  mitigate  this  the  trestle  would  be 
made  considerably  higher. 

The  kind  of  ropeway  just  described  is  known  as  a 
double  rope  or  bi-cable  line,  and  under  certain  con- 
ditions they  are  to  be  preferred  to  any  other.  The  kind 
adopted  for  the  Dorada  Ropeway  is  a  newer  type  in 
which  one  cable  does  everything,  and  which  is,  there- 
fore, called  a  mono-cable,  or  single  rope  line. 

Imagine  a  long  rope  of  steel  with  its  ends  spliced 
together  so  that  it  is  endless,  looped  round  two 
large  grooved  wheels  about  8  ft.  in  diameter,  the  two 
wheels  being  several  miles  apart.  The  two  halves  of 
the  rope  will  be  parallel,  separated  by  a  distance  of 
8  ft.,  and  if  the  two  wheels  be  turned  round  one  part 

274 


A  RAILWAY  IN  THE  AIR 

of  the  rope  will  travel  in  one  direction  and  one  part 
in  the  other. 

Further,  imagine  these  8-ft.  wheels  to  be  secured 
to  a  suitable  steel  framework,  so  that  the  rope  can 
be  stretched  with  any  desired  degree  of  tightness, 
and  finally  picture  a  long  row  of  trestles  supporting 
the  rope  at  intervals  and  you  will  have  a  good  mental 
picture  of  this  wonderful  installation. 

In  this  case,  of  course,  the  ropes  are  not  fixed  to 
the  trestles,  but  are  simply  supported  by  grooved 
wheels  carried  upon  the  trestles,  the  wheels  revolving 
as  the  rope  passes  over  them. 

The  buckets  or  other  receptacles  for  goods  are 
attached  to  clips  which  hook  over  the  rope,  being 
so  shaped  that  they  can  pass  over  the  grooved  wheels 
on  the  trestles  without  being  thrown  off  the 
rope. 

Herein  lay  one  of  the  chief  difficulties  in  the  use  of 
a  single  rope,  for  at  first  it  was  thought  impossible 
to  devise  a  form  of  clip  which  would  be  able  on  the 
one  hand  to  grip  the  rope  firmly  enough  not  to  slip 
on  an  incline,  and  on  the  other  capable  of  passing 
over  the  wheels.  After  much  experimenting  the 
problem  was  solved  by  Mr.  J.  P.  Roe,  an  engineer 
who  specialized  for  years  in  ropeway  matters  and 
who  was  largely  interested  in  the  Dorada  Ropeway. 
He  found  that  if  he  made  a  simple  hook-shaped 
clip  to  go  over  the  rope,  with  a  single  small  pro- 
jection upon  it  of  such  a  shape  that  it  lay  in  between 
the  strands  of  the  rope,  no  slip  would  take  place  on 
all  reasonable  inclines.  The  elaborate  and  costly 
mechanical  forms  of  grip  which  had  previously  been 

375 


A  RAILWAY  IN  THE  AIR 

thought  essential  and  which  presented  all  manner 
of  difficulties  were  found  to  be  quite  unnecessary. 

It  may  be  said  without  exaggeration  that  this  kind 
of  ropeway,  with  its  many  advantages  over  the  older 
type,  was  only  made  possible  by  this  beautifully 
simple  invention. 

But  perhaps  some  readers  may  wonder  why  this 
difficulty  does  not  arise  equally  in  those  cases  where 
the  thing  is  hauled  along  by  a  separate  rope,  for  the 
trolleys  must  of  necessity  be  detached  from  the 
hauling  rope  in  that  case  also.  The  answer  is  that 
the  hauling  rope  in  a  bi-cable  system  does  not  need 
to  pass  closely  through  the  groove  upon  the  edge  of 
a  revolving  wheel. 

The  large  wheels  around  which  the  rope  passes  at 
each  end  are  mounted  in  specially  constructed  steel 
frames.  That  at  one  end,  called  the  driving  end, 
has  a  tooth  wheel  coupled  to  it  by  means  of  which 
it  is  driven  round,  the  power  being  derived  from  a 
steam  engine  or  other  form  of  motor. 

At  the  other  end,  the  "  tension  "  end,  the  wheel 
is  mounted  upon  a  small  trolley  which  runs  upon 
rails  embodied  in  the  frame,  and  is  pulled  back  by 
means  of  a  heavy  weight,  thus  ensuring  that  the 
correct  tension  shall  be  kept  upon  the  main  rope. 

A  loaded  bucket,  upon  arrival  at  its  destination, 
is,  by  beautifully  simple  means,  shunted  off  the  rope 
on  to  a  "  shunt  rail,"  which  is  mounted  upon  the 
top  of  the  station  frame.  The  rope  comes  into  the 
station  at  a  certain  angle  ;  there  it  passes  over  a 
pulley,  after  which  it  takes  a  slightly  downward 
direction  to  the  large  wheel,  which  is  set  at  the 

276 


A  RAILWAY  IN  THE  AIR 

correct  angle  to  receive  it.  Having  passed  round 
the  large  wheel  it  comes  upward  once  more,  passes 
over  another  wheel  and  goes  out  slightly  downwards. 


Fig.  20. — DIAGRAM  SHOWING  HOW  THE  RAIL  LIFTS  THE 

LOAD  OFF  THE  ROPE. 
(Details  much  altered,  for  simplicity.) 

As  the  rope  descends,  at  the  station,  the  roller  engages  with 
the  rail  which  supports  the  whole  thing,  while  the  rope  with- 
draws itself  from  the  clip. 

The  shunt  rail  is  practically  horizontal,  one  end 
being  near  the  first  wheel  just  mentioned  and  the 
other  end  near  the  one  last  mentioned.  Further, 
each  clip  has  connected  with  it  two  small  grooved 

277 


A  RAILWAY  IN  THE  AIR 

rollers  which,  when  the  thing  is  on  the  rope,  do 
nothing. 

The  bucket,  then,  comes  sailing  in,  so  to  speak. 
After  passing  the  first  wheel  the  rope  changes  its 
direction  downwards,  thereby  dropping  the  two 
rollers  on  to  the  shunt  rail.  The  rollers  thus  take 
the  weight  of  the  bucket,  lift  it  off  the  rope,  as  the 
latter  moves  downwards,  and  leave  it  free  to  be  run 
along  the  shunt  rail  to  the  desired  position  for  un- 
loading. After  being  unloaded  the  bucket  is  pushed 
along  the  shunt  rail  until  the  process  is  reversed  ; 
the  rope  coming  upwards  gets  under  the  clip,  lifts 
the  rollers  off  the  rail  and  carries  the  bucket  away. 

What  has  been  said  up  to  the  present  is  little  more 
than  a  description  of  ropeways  in  general.  It  was 
necessary  in  order  to  make  intelligible  the  account 
of  the  marvellous  installation,  which  really  forms 
the  subject  of  this  chapter. 

The  total  length  of  this,  as  has  been  said,  is  about 
forty-five  miles,  but  it  must  not  be  thought  that  the 
ropes  run  continuously  for  that  distance.  It  is 
divided  up  into  sixteen  sections.  It  might  thus  be 
said  to  be  sixteen  ropeways  placed  end  to  end. 
They  are  not  really  separate,  however,  because  at 
the  intermediate  stations  the  shunt  rails  are  so 
arranged  that  a  bucket  coming  in  from  one  section  is 
passed  on  to  the  next  section  instead  of  being  sent 
back,  as  would  be  the  usual  arrangement. 

The  division  of  the  line  into  sections  also  has  the 
advantage  of  enabling  it  to  follow  a  more  or  less  zig- 
zag route,  thereby  serving  a  number  of  intermediate 
villages,  for,  of  course,  each  section  has  to  be  straight, 

278 


A  RAILWAY  IN  THE  AIR 

for  otherwise  the  rope  would  never  lie  comfortably 
in  the  wheels  which  support  it.  The  longest  of  the 
sections  is  5800  metres,  and  the  shortest  2590.  The 
former  rises  240  metres,  but  the  latter,  although  so 
much  shorter,  rises  nearly  400  metres,  and  it  is  this 
steep  gradient  which  necessitates  the  section  being- 
short,  because  if  it  were  longer  the  pull  of  a  large 
number  of  buckets  would  be  too  much  for  the  rope. 


Fig.  21, 

This  diagram  shows  how  the  loads  are  passed  from  one  section 
of  ropeway  to  the  next. 

On  arrival  at  A,  the  rope  dips  downwards,  leaving  the  load 
supported  by  its  rollers  upon  the  shunt  rail.  The  load  is  pushed 
along  the  rail  to  B,  where  the  opposite  occurs,  the  rising  rope 
engaging  in  the  clip  lifting  the  load  off  the  rail  and  carrying  it 
away.  At  the  end  station  the  shunt  rail  curves  round  some- 
what as  shown  dotted. 


The  stations  are  arranged  alternately,  so  that 
with  one  exception  two  driving  stations  always  come 
together  and  two  tension  stations,  thereby  keeping 
the  number  of  points  where  power  is  required  down 
to  the  minimum. 

The  power  is  derived  from  steam  engines,  of  which 
a  number  each  of  30  horse-power  were  sent  out  from 
England.  Where  30  horse-power  is  not  enough  two 
engines  are  employed.  The  boilers  are  made  with 

279 


A  RAILWAY  IN  THE  AIR 

specially  large  fire-boxes,  so  that  wood  fuel,  which  is 
plentiful  in  the  neighbourhood,  can  be  used.  Engines 
and  boilers  alike  were  specially  designed  so  that  they 
could  be  taken  to  pieces  for  transport,  and  no  single 
piece  weighed  more  than  10  cwt.,  the  great  bulk  of 
the  material  being  actually  packed  in  cases  of  not 
more  than  2  cwt. 

This  was  necessary  because  of  the  system  adopted 
throughout  of  making  a  finished  section  carry  the 
material  for  the  next  one,  and  the  further  need 
of  transporting  over  intermediate  distances  by 
mules. 

The  rope  itself  weighed  the  astonishing  amount  of 
255  tons.  It  has  a  circumference  of  2f  ins.,  and  is 
constructed  of  steel  wires,  having  a  breaking  strain 
of  105  tons  per  square  inch.  The  actual  rope  has  a 
less  degree  of  strength  than  that,  because,  of  course, 
it  is  not  solid  wire,  but  has  a  number  of  spaces  in 
between.  The  load  necessary  to  break  the  rope  is 
just  over  30  tons. 

It  is,  of  course,  impossible  to  divide  the  rope  up 
into  small  pieces  for  transport,  as  was  done  with  the 
engine  and  other  parts,  for  that  would  mean  too 
many  splices.  The  same  result  is  attained,  however, 
by  making  it  into  small  coils  with  a  length  of  loose 
rope  between.  The  coils  are  then  tied  in  pairs  and 
slung  one  each  side  of  a  mule,  the  intervening  lengths 
of  straight  rope  stretching  from  mule  to  mule.  The 
animals  are  thus  tied  together,  much  after  the  fashion 
of  alpine  climbers,  and  many  anxious  moments  there 
were  when  one  mule  in  a  long  train  showed  a  ten- 
dency to  slip  on  a  mountain  track,  for  if  he  had  gone 

280 


A  RAILWAY  IN  THE  AIR 

the  whole  train  might  have  followed  him,  together 
with  some  tons  of  rope,  down  the  mountain  side. 

The  trestles  number  437,  some  as  low  as  3  metres, 
but  one,  at  least,  reaching  66  metres,  about  five  times 
the  height  of  an  ordinary  three-storey  house. 

All  the  smaller  ones  were  of  a  kind  specially 
developed  by  Messrs.  Ropeways,  Limited,  the  con- 
tractors for  the  line,  in  which  a  lot  of  small  pieces 
are  sent  out  in  bundles  and  put  together  on  the  spot, 
much  as  boys  build  things  with  "  meccano."  They 
are  tripod  arrangements,  the  three  legs  being  joined 
together  at  intervals  by  horizontal  struts,  and  then 
the  whole  tied  together  with  diagonal  rods,  which 
can  be  tightened  up  by  screwing  them  round. 

Where  a  very  tall  trestle  was  needed  a  special  base 
was  designed,  and  then  one  of  these  standard  ones 
put  on  the  top  of  it. 

In  other  cases,  where  the  load  upon  a  trestle  is 
very  heavy  a  stronger  kind  of  structure,  with  four 
legs,  was  used  instead  of  these. 

At  each  trestle  a  pair  of  stout  steel  beams  are 
fixed  projecting  out  horizontally  on  either  side,  to 
carry  the  "  sheaves."  Where  only  one  single  sheave 
is  required  the  spindle  upon  which  it  turns  is  fixed 
to  the  end  of  this  beam,  but  such  cases  are  not 
frequent.  The  pressure  of  the  rope  is  generally  too 
great  to  be  taken  safely  by  one  sheave,  so  that  two, 
four  and  in  some  cases  eight  are  used.  But  it  would 
clearly  be  no  use  to  increase  the  number  of  the 
sheaves  unless  it  could  be  made  sure  that  each  one 
would  take  its  fair  share  of  the  load,  but  that  diffi- 
culty is  overcome  in  a  very  interesting  way. 

281 


A  RAILWAY  IN  THE  AIR 

Let  us  take  first  of  all  a  pair.  In  this  case,  a  short 
beam  is  pivoted  on  the  end  of  the  main  beam,  and  one 
sheave  is  placed  at  each  end.  Thus  the  "  pair  beam," 
as  it  is  termed,  can  see-saw,  and  whatever  the  pres- 
sure on  the  rope  may  be  and  at  whatever  angle  it 
may  pull,  each  sheave  takes  exactly  half.  If  there 
be  four  sheaves  a  larger  beam  is  balanced  upon  the 
end  of  the  main  beam,  this  one  being  termed  a 
"  quad  beam,"  carrying  at  each  end  a  pair  beam 
with  its  two  sheaves.  Thus  the  pair  beams  see-saw 


Fig.  22. — How  THE  ROPES  ABE  SUPPORTED  WHERE  THE 

LOADS    ARE    VERY    HEAVY. 

Eight  wheels  are  used,  and  seven  beams.  One  beam  is 
supported  upon  the  trestle  at  A.  This  in  turn  supports  two 
others  at  B.  These,  again,  carry  four  others  at  C,  and  these 
carry  the  wheels. 

All  the  beams  are  free  to  rock  upon  their  centres,  with  the 
result  that  all  the  wheels  are  ''alive,"  and  each  has  to  do 
exactly  its  fair  share  of  the  work. 

upon  the  ends  of  the  quad  beams  and  the  quad 
beam  upon  the  end  of  the  main  beam. 

The  same  principle  prevails  when  the  sheaves 
number  eight,  an  "  octo  "  beam  being  first  supported 
upon  the  end  of  the  main  beam,  two  quad  beams 
upon  that,  and  four  pair  beams  upon  them,  eight 
sheaves  completing  the  whole  series.  The  result  of 
all  this  is  that,  whatever  the  load  may  be,  all  the 
sheaves  get  their  fair  share  and  no  more. 

Normally  the  limit  for  each  load  is  6  cwt.,  but  by 
special  arrangement  as  much  as  10  cwt.  can  be 

282 


A  RAILWAY  IN  THE  AIR 

carried.  The  speed  of  the  line  is  120  metres  per 
minute,  or  four  and  a  half  miles  per  hour,  and  the 
loads  follow  each  other  at  the  rate  of  about  one 
every  two  minutes. 

The  vehicles,  as  one  might  call  them,  in  which  the 
goods  are  carried  are  of  various  kinds,  according  to 
what  has  to  be  carried.  For  some  things  buckets 
are  used,  for  others  a  kind  of  wooden  platform  with 
an  iron  sling  is  found  most  convenient,  while  for 
long  articles  a  pair  of  carriers  some  distance  apart, 
but  coupled  together  with  a  flexible  connection,  are 
used. 

The  operation  of  the  line  soon  had  its  effect  upon 
the  commerce  of  the  district,  the  amount  of  coffee 
exported,  to  give  only  one  instance,  increasing  in  a 
few  years  from  9000  to  18,000  tons.  As  time  goes  on 
this  will  no  doubt  increase,  until  the  line  will  be 
working  at  its  full  capacity  of  20  tons  per  hour  in 
the  downward  direction,  towards  Mariquita,  and 
10  tons  per  hour  the  other  way. 


283 


CHAPTER  XXI 
FIGHTING  NATURE  IN  CANADA 

IN  a  previous  chapter  we  had  a  brief  review  of  the 
difficulties  encountered  in  surveying  for  and 
plotting  out  the  course  of  the  Grand  Trunk 
Pacific  Railway.  Now  we  will  look  at  some  of  the 
tasks  which  confronted  the  men  who  actually  con- 
structed the  line. 

Naturally,  in  a  line  of  such  length,  there  were 
many  varieties  of  country  to  be  crossed.  For  a 
part  of  its  length  the  country  was  flat  prairie,  where 
little  had  to  be  done  except  lay  the  rails.  The 
ground  was  already  flat  and  firm. 

In  other  places,  however,  the  difficulties  were  such 
as  to  make  up,  many  times  over,  for  the  ease  of 
working  upon  the  prairie.  There  were  dense  forests 
to  be  cut  through,  swamps  to  be  crossed,  bridges 
to  be  built,  and  in  some  spots  rock  was  encountered 
in  a  particularly  annoying  form. 

It  was  just  as  if  huge  pieces  of  rock  had  been 
flung  about  promiscuously  by  giants  at  play.  The 
rocks  were  too  rough  and  detached  to  form  the  bed 
of  the  line,  they  were  too  close  for  the  line  to  pass 
between,  and  the  only  thing  was  to  hew  a  way 
through  them. 

The  work  was,  of  course,  started  at  the  two  ends, 

284 


FIGHTING  NATURE  IN  CANADA 

and  in  addition  it  was  attacked  at  several  intermediate 
points  where  transport  was  possible.  Several  lakes 
and  convenient  water-ways  materially  assisted  in  this. 

The  most  convenient  way  to  work  is  obviously 
from  an  end,  because  as  the  line  proceeds  the 
materials,  tools  and  men  can  be  brought  along  it 
to  the  rail-head.  Every  yard  that  is  made  becomes 
a  tool  for  use  in  making  the  next  yard. 

On  a  long  line,  however,  the  work  would  progress 
but  slowly  if  it  were  carried  on  only  from  the  two 
ends.  Yet  if  it  be  through  wild  country  it  may  be 
exceedingly  difficult  to  get  the  necessary  men  and 
material  to  any  intermediate  point.  Consequently, 
a  friendly  water-way,  even  if  it  be  somewhat  incon- 
venient, may  be  a  welcome  help  if  it  gives  access 
to  an  intermediate  point.  No  doubt  this  matter  was 
given  due  consideration  when  deciding  upon  the 
precise  course  of  the  line. 

The  task  confronting  the  engineers  was  to  form,  by 
some  means  or  other,  a  smooth  level  track  100  ft. 
wide  and  about  3500  miles  long,  so  that  the  need 
for  intermediate  starting  points  is  evident. 

Let  us  take  first  the  forest  country.  Here  the 
trees  were  felled  and  the  undergrowth  cut  away  by 
armies  of  men  with  axes  and  similar  tools.  The  debris 
was  piled  in  the  centre  of  the  track  and  burnt  in  huge 
bonfires.  At  least,  that  happened  to  all  such  as  was 
not  required  for  use  in  the  construction  operations. 
Great  care  was,  of  course,  taken  not  to  do  this  burn- 
ing when  the  conditions  favoured  forest  fires,  and 
every  precaution  was  observed  to  see  that  damage 
was  not  done. 

285 


FIGHTING  NATURE  IN  CANADA 

As  the  track  was  thus  cleared,  camps  were  formed 
for  the  accommodation  of  the  men,  and  narrow- 
gauge  lines  were  laid  down  temporarily  to  carry 
materials.  These  narrow-gauge  lines  were  followed 
in  due  course  by  other  lines,  temporary  also,  but  of 
the  standard  gauge. 

After  having  been  cleared  of  vegetation,  the  ground 
had  to  be  levelled  ;  humps  had  to  be  cut  away  and 
hollows  filled  up,  and  in  this  all  manner  of  mechanical 
aids  were  employed  to  supplement  the  work  of 
men's  hands.  Of  these  may  be  mentioned  the 
"  grading  machine." 

This  is  something  like  a  plough  in  its  action  in 
that  it  has  a  knife  which,  when  the  machine  is  pulled 
along,  cuts  into  the  earth.  It  is  drawn  by  many 
horses,  perhaps  a  dozen,  in  three  rows  of  four,  hauling 
it  from  the  front,  while  as  many  push  it  from  behind. 
As  the  knife  scoops  up  the  earth  a  small  chain  with 
buckets  attached  is  moved  along,  lifting  the  spoil 
automatically  and  dropping  it  into  the  attendant 
carts. 

This  machine  can  only  be  used  where  the  earth  is 
fairly  soft,  but  in  such  cases  it  is  such  a  saver  of  human 
labour  as  to  be  very  valuable  indeed. 

What  is  done  with  the  "  spoil  "  depends  upon 
circumstances.  If  there  are  hollows  to  be  filled  in 
it  is  used  for  that.  If  embankments  require  to  be 
made  it  may  be  hauled  for  miles  along  the  temporary 
lines  for  that  purpose,  but  if  no  use  presents  itself 
it  is  tipped  into  a  ravine,  or  otherwise  got  rid  of  in 
the  easiest  possible  way. 

In  many  parts  of  the  line  swamps  were  encountered, 

286 


I 


FIGHTING  NATURE  IN  CANADA 

or  places  known  by  the  local  name  of  muskeg.  This 
latter  term  means  apparently  something  between  a 
swamp  and  dry  land,  land  which  is  nearly  dry,  but 
which  is  so  soft  that  it  cannot  support  a  heavy 
weight.  A  horse,  were  it  to  cross  a  muskeg,  would 
find  its  feet  sinking  in,  and,  of  course,  a  railroad 
would  be  far  too  heavy  a  load  for  it  to  support. 

The  muskegs  were  crossed  by  means  of  the  roads 
called,  in  that  part  of  the  world,  "  corduroy."  These 
consist  of  rough  logs  of  wood  laid  down  together, 
parallel  and  in  close  contact ;  presumably  it  is  the 
resemblance  of  such  a  road  to  the  familiar  fabric 
called  "  corduroy "  which  has  given  rise  to  the 
term. 

Anyway,  these  logs  so  spread  the  weight  of  a 
passing  man  or  vehicle  that  passengers  and  carts 
can  freely  travel  over  the  muskeg  on  corduroy  roads. 
They  will  not  carry  a  railway,  however,  so  to  make 
the  permanent  road  other  logs  are  laid  on  the  first 
layer,  at  right  angles,  and  to  these  are  added  brush- 
wood and  branches  until  a  thick  "  mattress "  is 
formed  several  feet  thick.  Upon  this  earth  is  laid, 
the  weight  of  which  causes  the  mattress  to  be  pressed 
into  the  soft  ground,  until  at  last  a  condition  is 
reached  when  added  weight  causes  no  further  sinking. 
Then  the  ground  is  firm  and  strong  enough  for  the 
railway  to  be  laid. 

It  is  rather  interesting  to  remember  that  this  form 
of  construction  over  soft  ground  may  fairly  be 
attributed  to  the  original  George  Stephenson,  for 
that  is  just  how  he  carried  the  Manchester  and 
Liverpool  line  over  Chat  Moss,  near  Manchester. 

287 


FIGHTING  NATURE  IN  CANADA 

In  the  case  of  swamps,  which  are  much  softer 
and  more  wet,  a  more  primitive  method  is  employed. 
The  swamp  is  simply  treated  as  if  it  were  not  there, 
or  rather  as  if  it  were  an  empty  hollow.  The  line  is 
brought  to  the  edge  and  earth  is  tipped  in.  At  first 
this  sinks,  and  it  seems  as  if  all  were  labour  in  vain, 
but  after  a  time,  a  very  long  time  in  some  cases,  the 
earth  ceases  to  sink  in,  which  is  a  sign  that  at  last 
an  embankment  is  beginning  to  form  upon  the  hard 
bottom  of  the  swamp.  Then  the  line  is  carried  for- 
ward a  little  on  to  the  firm  ground  thus  formed  and 
more  earth  is  tipped  so  that  the  embankment  shall 
be  elongated,  until  at  last  it  has  been  carried  right 
across  the  swamp. 

And  yet  another  way  was  employed  in  some  cases 
upon  this  wonderful  line.  Trees  were  cut  down  and 
driven  in  like  stakes  into  the  bed  of  the  swamp. 
The  tops  of  these  being  joined  together  by  other 
logs,  eventually  formed  a  light  and  somewhat  flimsy 
gangway  across  the  swamp,  over  which  the  light 
narrow-gauge  line  could  be  carried.  Then  day  by 
day  trucks  poured  along  this  structure,  each  de- 
positing its  load  of  earth  until  the  whole  gangway 
itself  had  become  buried  in  a  solid  bank  of  earth. 
This  is  a  particularly  quick  and  effective  way  for 
forming  an  embankment  across  a  swamp. 

As  has  been  remarked  already,  the  country 
traversed  by  this  line  is  in  parts  cut  up  by  small 
rivers  and  ravines  all  running  at  right  angles  to  the 
line  of  route.  This  is  particularly  annoying,  because 
it  necessitates  a  large  number  of  small  bridges,  and  if 
the  engineers  had  waited  to  build  one  bridge  at  a 

288 


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FIGHTING  NATURE  IN  CANADA 

time  there  would  have  been  great  delay.  On  the 
other  hand,  how  could  the  material  be  got  across  for 
the  second  bridge  until  the  first  had  been  made,  and 
in  like  manner,  how  could  the  third  be  constructed 
until  the  second  had  been  finished  ? 

The  only  thing  to  do  was  to  utilize  the  timber 
which  was  so  plentiful  and  run  up  rough,  temporary 
bridges  of  timber  to  carry  the  temporary  line,  pending 
the  completion  of  the  permanent  bridges.  This 
enabled  a  number  of  the  latter  to  be  got  on  with 
simultaneously. 

A  curious  trouble  was  encountered  in  some  parts 
of  the  line.  An  embankment  would  be  completely 
finished  and  apparently  as  sound  as  a  bell,  when 
suddenly  a  short  length  of  it,  perhaps  a  hundred  feet 
or  so,  would  sink  several  feet.  It  was  as  if  a  weak 
place  developed  in  the  solid  earth  and  allowed  the 
embankment  to  sink  in.  As  .a  rule,  it  was  only 
necessary  to  add  more  earth  at  the  top  of  the  em- 
bankment so  as  to  bring  the  top  up  to  the  correct 
level  once  more. 

The  rocky  country,  needless  to  say,  had  to  be 
dealt  with  on  a  different  manner.  Dynamite  was  the 
king  of  this  portion  of  the  work.  Men  were  collected 
from  all  parts  who  were  skilled  in  the  use  and  handling 
of  this  valuable  aid  to  the  engineer.  The  air  was 
filled  with  the  sound  of  hammers  striking  upon  the 
drills  with  which  the  holes  were  made  in  the  rock, 
while  at  intervals  the  deep  roar  of  an  explosion  would 
roll  over  the  wilderness. 

At  one  spot  a  whole  cliff  had  to  be  removed,  and  for 
this  purpose  a  shaft  was  sunk,  almost  like  a  well, 

T  289 


FIGHTING  NATURE  IN  CANADA 

at  the  bottom  of  which  was  buried  a  charge  of 
dynamite  of  unprecedented  size.  The  explosion 
which  followed  in  due  course  moved  30,000  tons  of 
rock. 

Probably  during  the  war  far  greater  explosions 
were  brought  about,  but  when  this  was  done,  just 
before  the  war,  it  must  have  been  almost  a  record. 

One  of  the  strange  things  about  the  use  of  explo- 
sives is  that  the  men  get  remarkably  careless.  The 
science  of  explosives  has  been  brought  to  such  a 
pitch  that  dynamite,  properly  handled,  is  perfectly 
safe.  It  will  only  go  off  under  certain  well-known 
conditions,  and  if  these  conditions  be  carefully 
avoided,  dynamite  can  be  handled  as  safely  as  coal. 

Thus  the  men  get  careless.  They  handle  it  so 
often  with  safety  that  they  eventually  forget  that 
there  is  any  danger  in  it  at  all,  and  then  they  oft- 
times  have  to  pay  the  extreme  penalty. 

Particularly  is  this  the  case  during  the  winter  when 
the  dynamite  is  apt  to  get  frozen.  In  such  condition 
it  is  useless  and  has  to  be  thawed,  for  which  reason 
the  men  frequently  put  it  in  front  of  a  stove,  or  per- 
haps on  a  stove  or  even  in  an  oven.  But  after  being 
frozen  and  then  thawed  the  dynamite  is  in  a  specially 
sensitive  state,  far  more  so  than  usual,  but  the  men 
forget  this  and  danger  results. 

It  has  been  said,  and  it  is  a  fine  testimony  to  the 
inherent  goodness  of  even  the  roughest  men,  that 
the  only  way  by  which  the  engineers  can  instil  care 
into  the  men  who  handle  explosives  is  by  appealing 
to  their  care  for  others.  The  risk  to  themselves  does 
not  seem  to  trouble  them  in  the  slightest  degree, 

290 


FIGHTING  NATURE  IN  CANADA 

but  the  thought  that  by  carelessness  they  may 
imperil  others  does  seem  to  impress  them,  and  for 
the  sake  of  others  they  will  take  pains  which  they 
refuse  to  take  in  their  own  interest. 

Another  thing  which  these  men  will  not  do  is  to 
take  due  care  to  avoid  the  flying  fragments  which 
follow  the  explosion.  Due  arrangements  are  made 
for  safe  refuges  for  the  men,  in  which  they  can 
shelter  while  the  pieces  of  rock  are  flying  about,  but 
the  men  frequently  neglect  to  take  advantage  of 
these. 

Another  thing  which  they  will  persist  in  doing  is 
to  rush  back  and  start  work  again  before  they  are 
sure  that  all  the  charges  have  exploded.  Frequently 
several  charges  are  laid,  and  if  all  goes  well  these 
should  work  simultaneously,  or  nearly  so,  but  some- 
times one  will  fail.  Then  it  may  lie  dormant  for  a 
time,  to  be  awakened  later  by  a  chance  stroke  of  a 
pick  or  something  of  that  sort  and  an  explosion  will 
follow. 

Owing  to  these  risks  this  part  of  the  work  was  the 
most  costly  in  human  lives  of  any  part  of  the  under- 
taking. 

Let  us  now  picture  to  ourselves  the  track  for  the 
line  duly  prepared,  that  is  to  say,  a  roughly  level 
strip  ready  for  the  ballast,  sleepers  and  rails.  The 
laying  of  the  rails  was  done  by  a  very  remarkable 
machine,  known  as  a  "  track-layer." 

This  consists  of  a  large,  heavy  truck,  with  a  special 
form  of  crane  mounted  upon  it,  which  is  pushed  along 
from  behind  by  a  locomotive.  Immediately  behind 
the  machine  itself  there  follows  a  truck  piled  high 

291 


FIGHTING  NATURE  IN  CANADA 

with  rails,  then  the  locomotive  and  finally  trucks 
with  sleepers. 

On  one  side  of  the  track-layer  is  an  iron  trough 
with  a  number  of  short  rollers  in  it,  the  rollers  being 
driven  round  by  a  steam  engine  on  the  machine 
itself.  This  trough  extends  backwards  for  a  con- 
siderable distance,  as  far,  in  fact,  as  the  trucks  of 
sleepers. 

When  in  action  the  whole  train,  as  just  described, 
stands  upon  the  rails  just  laid,  the  track-layer  being 
quite  close  to  the  end.  Men  in  the  trucks  behind 
throw  sleepers  on  to  the  rollers  in  the  trough,  which, 
since  they  are  revolving,  carry  them  forward  and 
shoot  them  down  upon  the  ground  just  where  they 
are  needed.  Here  a  powerful  gang  of  men  receive 
them  and  quickly  haul  them  into  place  until  enough 
sleepers  are  down  to  support  a  fresh  length  of  rail. 
Then  the  crane-like  structure  passes  along  two  rails 
from  the  truck  behind,  and  these  are  quickly  joined 
by  fishplates  to  the  ones  last  laid  and  spiked  down 
upon  the  sleepers.  It  should  be  explained  here  that 
on  this  line  chairs  are  not  used  as  in  the  European 
practice,  but  the  rails  have  a  flat  flange  on  the 
underside,  so  that  they  can  stand  directly  upon  the 
sleepers  with  nothing  more  than  a  square  plate  of 
iron  between  to  distribute  the  weight  upon  the 
wood,  and  the  rails  are  fastened  down  by  "  dog 
spikes,"  especially  formed  nails  of  huge  dimensions, 
the  heads  of  which  hook  over  the  edges  of  the  flange. 

In  this  way  the  line  is  roughly  laid,  and  the  track- 
layer with  its  attendant  engine  and  trucks  passes 
on.  The  line  is  not,  however,  by  any  means  finished, 

292 


FIGHTING  NATURE  IN  CANADA 

for  there  is  no  ballast  and  it  is  not  level.  Therefore 
the  ballast  train  follows.  This  consists  of  trucks 
with  doors  underneath,  so  that  as  the  train  slowly 
proceeds  the  ballast  can  be  let  out,  forming  a  ridge 
between  the  rails.  On  the  last  car  of  the  train  is  a 
"  distributer,"  a  kind  of  plough  which  is  drawn  along 
close  to  the  rails,  the  "  ploughshares "  being  so 
shaped  and  so  set  that  they  level  off  the  heap  of 
ballast  between  the  rails  and  throw  any  surplus  to 
the  sides. 

That  is  about  as  far  as  mechanical  aids  can  go. 
The  human  mind  is  required  for  the  last  step,  which 
is  to  level  and  straighten  out  the  line  and  pack  the 
ballast  carefully,  so  that  a  strong,  firm  line  may 
exist  capable  of  carrying  heavy  trains  at  a  high  speed. 

So  the  gangs  of  platelayers  come  along  to  put  in 
the  finishing  touches.  They  raise  those  parts  of  the 
rails  which  need  it  by  means  of  jacks,  straighten  the 
rails  where  necessary,  and  with  their  shovels  and 
beaters  place  the  ballast  beneath  and  around  the 
sleepers.  When  they  have  finished  with  the  job 
there  is  a  railway,  as  we  know  the  term,  a  carefully 
adjusted  and  well-cared  for  track,  along  which  the 
trains  can  move. 

This  takes  them  a  little  time,  particularly  upon 
embankments  and  other  places  where  the  ground 
has  been  made  up,  because  settlement  is  always  apt 
to  occur  at  such  places.  They  have  to  watch  the  line 
very  carefully,  therefore,  for  a  time,  jacking  up  and 
putting  new  ballast  as  may  be  necessary.  It  is  not 
long,  however,  before  the  line  is  ready  for  traffic. 

Thus  we  see  how  man,  with  his  persistency,  his 

293 


FIGHTING  NATURE  IN  CANADA 

ingenuity  and  his  natural  love  for  overcoming 
obstacles,  beats  Nature  in  her  wildest  moods  and 
brings  her  to  serve  his  own  needs. 

[The  information  contained  in  this  chapter  has  been  derived 
from  Mr.  F.  A.  Talbot's,  "  The  Making  of  a  Great  Canadian 
Railway,"  by  kind  permission  of  the  Author,] 


294 


CHAPTER  XXII 
LONG  ALPINE  TUNNELS 

THE  Continent  of  Europe  is  cut  up  by  the  high 
Alpine  Range.  Those  of  us  who  have  had  to 
wrestle  with  the  difficulties  of  translating  the 
writings  of  Caesar  will  remember  that  even  in  his 
time  the  Alps  were  great  obstacles  to  movement 
from  one  part  to  another.  With  the  larger  popula- 
tions of  to-day  and  the  greater  need  for  inter- 
communication between  nations,  these  old  obstacles, 
while,  of  course,  no  worse  actually  than  of  old, 
became  more  and  more  serious  in  the  inconvenience 
which  they  caused. 

Mountains,  naturally,  are  not  the  same  height  all 
along  the  range.  There  are  parts  which  are  lower 
than  others,  and  these  form  the  "  passes  "  over  the 
range.  A  pass  is,  of  course,  merely  a  convenient 
place  for  crossing  the  mountains,  but  the  reason  it  is 
convenient  is  because,  generally  speaking,  it  is  lower 
than  elsewhere ;  and  secondly,  the  action  of  streams 
and  rivers  have  usually  excavated  a  kind  of  transverse 
valley  leading  up  the  pass. 

Although  a  pass  is  a  hollow,  by  comparison  with 
the  surrounding  heights,  it  has,  nevertheless,  a 
summit  or  highest  point,  the  roadway  gradually 

295 


LONG  ALPINE  TUNNELS 

rising  to  it  from  one  side  and  then  falling  away 
again  on  the  other  side. 

To  illustrate  this  we  may  take  the  well-known 
St.  Gothard  Pass  in  Switzerland.  The  road  runs 
for  miles,  gradually  rising  towards  the  pass  itself, 
following  for  the  most  part  the  valley  which  has 
been  cut  by  the  River  Reuss  as  it  flows  from  the 
high  mountains  down  to  the  "  Lake  of  the  Four 
Forest  Cantons."  After  surmounting  the  pass  the 
road  descends  slowly  on  the  other  side  to  the  plains 
of  Italy. 

The  railway,  not  unnaturally,  follows  very  largely 
the  line  of  the  old  road  along  which  Napoleon  marched 
his  armies.  It  does  so  because  just  as  the  old  road- 
maker  sought  for  the  easiest  gradients,  so  does  the 
railway-maker  of  to-day. 

The  railway  engineer,  however,  is  not  satisfied 
with  the  conditions  which  were  deemed  good  enough 
for  road  traffic.  Consequently,  when  the  railway  has 
ascended  the  fairly  steep  road  to  the  foot  of  the  pass 
proper  it  boldly  leaves  it  to  the  road  to  scale  the 
steepest  part  of  the  route,  but  itself  dives  into  the 
mountain-side  and  passes  through  a  tunnel  over 
nine  miles  in  length  right  through  to  the  other  side. 

But  even  on  the  approach  to  the  tunnel  the  railway 
builder  has  resorted  to  devices  whereby  his  line 
shall  be  less  steep  than  the  roadway.  A  wonderful 
example  of  this  is  seen  on  the  St.  Gothard  line  at  the 
little  village  of  Wasen.  The  traveller,  in  passing 
this  beautiful  spot,  first  catches  a  glimpse  of  the 
village  church  high  above  him  on  the  mountain 
side,  he  being  then  at  the  bottom  of  the  little  valley. 


LONG  ALPINE  TUNNELS 

A  few  minutes  later  he  sees  the  church  again,  this 
time,  to  his  amazement,  about  on  the  same  level  as 
himself,  for  now  he,  too,  is  on  the  hill-side.  Again 
he  passes  into  a  tunnel,  on  emerging  from  which  the 
village  church  is  still  visible  and  close  at  hand,  but 
far  below,  for  he  is  now  on  the  hill-side,  even  higher 
up  than  the  church. 

The  explanation  of  this  is  that  tunnels  have  been 
employed  in  order  to  lengthen  out  the  track  and  so 
make  it  less  steep. 

The  line  comes  along  at  the  lowest  level,  enters  a 
tunnel  which  forms  a  wide  loop  right  inside  the 
mountain  ;  then,  after  a  short  interval  in  the  open 
air,  it  traverses  a  second  loop-like  tunnel,  rising 
steadily,  of  course,  all  the  time.  Both  road  and 
railway,  of  necessity,  rise  the  same  number  of  feet, 
but  the  increase  in  length  due  to  the  loop-shaped 
tunnels  enables  the  railway  to  rise  more  gradually. 
It  may  be  compared  roughly  to  a  spiral  staircase  cut 
in  the  inside  of  the  mountain. 

On  the  Italian  side  of  the  pass  a  similar  thing 
occurs,  but  there  the  tunnels  are,  if  anything,  more 
remarkable  still,  since  they  take  the  form  of  a  spiral 
or  corkscrew,  thus  making  a  descent  of  many  feet 
right  inside  the  mountain.  There  are  other  examples 
of  this  kind  of  construction  in  other  parts  of  the 
world. 

So  much  for  the  approaches  to  the  long  tunnels. 
Let  us  now  turn  to  the  tunnels  themselves. 

The  construction  of  these  involves  the  overcoming 
of  difficulties  not  met  with  in  shorter  tunnels.  For 
one  thing,  they  are  very  long  ;  for  another,  the  land 

297 


LONG  ALPINE  TUNNELS 

above  them  is  more  or  less  inaccessible  mountain, 
where  it  is  impossible  to  sink  shafts.  In  ordinary 
tunnels  of  any  considerable  length  shafts  are  sunk 
at  one  or  more  points  along  the  line,  and  from  the 
bottom  of  the  shafts  boring  is  carried  on  in  both 
directions.  This  one  shaft  will  roughly  halve  the 
time  necessary  to  construct  a  given  tunnel,  because 
operations  can  be  carried  on  from  four  points  instead 
of  two.  Two  shafts  will  give  six  points  instead  of 
two,  so  that  two  shafts  will  reduce  the  time  by  two- 
thirds,  and  so  on.  Devices  of  this  kind  are  impossible 
with  the  Alpine  tunnels,  and  so  the  work  has  to  be 
done  from  the  two  ends  only. 

Another  great  difficulty  is  the  heat.  As  you  bore 
farther  and  farther  into  the  earth  the  temperature 
always  increases.  This  is  found  in  sinking  wells, 
where  the  rise  is  about  one  degree  Fahrenheit  for 
every  60  ft.  in  depth,  and  the  experience  in  these  long 
tunnels  shows  that  this  rise  in  temperature  is  largely 
dependant  upon  the  depth  below  the  surface,  for  in 
the  Simplon  Tunnel,  which  is  about  twelve  miles 
long,  it  was  found  that  the  temperature  was  about 
one  degree  higher  for  every  67  ft.  of  depth  below  the 
surface.  Right  at  the  centre  of  this  tunnel,  where 
there  was  a  great  mass  of  mountain  lying  above,  the 
temperature  of  the  rock  was  found  to  be  133  degrees. 

This  heat  used  to  be  attributed  entirely  to  the 
greater  proximity  to  the  centre  of  the  earth,  where, 
no  doubt,  a  much  greater  temperature  exists  than 
upon  the  surface,  since  heat  must  have  been  escaping 
freely  from  the  surface  for  ages,  whereas  that  in  the 
centre  can  only  escape  much  more  gradually.  This, 

298 


LONG  ALPINE  TUNNELS 

however,  did  not  seem  to  be  quite  sufficient  to  account 
for  the  very  rapid  increase  of  temperature  with 
depth,  and  it  is  now  believed  to  be  due  to  a  very 
large  extent  to  that  newly  discovered  property  of 
certain  matter  called  "  radio-activity." 

Everyone  has  heard  of  "  radium,"  that  strange 
substance  which  is  continually  throwing  off  tiny 
particles  which  under  certain  conditions  can  be 
seen  like  microscopic  fireworks.  It  is  found,  too, 
that  the  immediate  surroundings  of  a  minute  quantity 
of  radium  are  always  slightly  higher  in  temperature 
than  things  less  close.  It  is  evident,  therefore,  that 
radium  also  gives  off  heat,  and  apparently  it  is  able 
to  keep  on  giving  off  heat  for  a  very  long  time  ;  in 
other  words,  the  amount  of  heat  stored  up  in  radium 
must  be  very  great  indeed. 

This  throwing  off  of  heat  and  of  small  particles 
is  called  "  radio-activity,"  and  is  apparently  due  to 
the  breaking  up  of  the  atoms  of  which  the  stuff 
consists. 

Now  radium  is  a  very  rare  substance,  but  since  it 
is  so  very  active  a  very  small  quantity  of  it  dis- 
tributed through  the  rocks  which  form  the  mountains 
might  easily  cause  this  mysterious  increase  in  tem- 
perature. Moreover,  although  radium  is  the  out- 
standing example  of  radio-activity,  there  are  other 
substances  which  do  the  same  thing,  though  to  a  less 
marked  degree,  and  it  may  be  the  presence  of  these 
things  in  the  rock  which  gives  rise  to  the  heat,  even 
though  radium  itself  may  be  absent. 

However  that  may  be,  this  rise  in  temperature  is 
a  very  serious  obstacle  to  the  engineers  who  are 

299 


LONG  ALPINE  TUNNELS 


responsible  for  the  boring  of  a  long  tunnel.  The 
measures  taken  to  combat  it  are  usually  two  ;  first, 
the  supply  of  ample  quantities  of  fresh  air,  which  is 
driven  into  the  tunnel  as  it  is  made  by  huge  fans, 
frequently  operated  by  the  many  streams  of  water 
to  be  found  in  the  vicinity  of  such  work ;  and  second, 
a  supply  of  cold  water  conveyed  through  pipes  and 
sprayed  about  the  workings,  so  as  to  cool  both  the 
rock  itself  and  the  air. 

When  the  tunnel  is  once  through,  that  is  to  say 
when  the  two  borings  have  met  in  the  interior  of 
the  mountain,  the  trouble  is  to  some  extent  solved 
automatically,  because  the  barometer  is  nearly  always 
higher  on  one  side  of  the  mountain  than  on  the  other* 
with  the  result  that  there  is  induced  a  natural  flow 
of  air  through  the  tunnel. 

In  the  case  of  the  Simplon  Tunnel,  where,  on 
account  of  the  enormous  length,  this  difficulty  was 
more  marked  than  in  .any  other  case,  special  methods 
were  adopted  which  will  be  mentioned  later. 

The  lengths  of  the  chief  Alpine  tunnels  are  as 
follows  :  Arlberg,  6J  miles  ;  Mont  Cenis,  8  miles  ; 
St.  Gothard,  9|  miles,  and  Simplon,  12 J  miles. 

The  variations  in  length  are  largely  due  to  the 
varying  heights  at  which  the  engineers  decided  to 
abandon  the  open  air  and  start  boring  into  the 
mountain.  Obviously,  it  is  cheapest  to  make  as 
much  of  the  line  as  possible  in  the  open  air,  and  in 
one  case  of  an  Alpine  pass,  the  Brenner,  they  actually 
succeeded  in  keeping  to  the  open  air  all  the  way, 
and  carrying  the  rails  right  over  the  pass  itself. 
That  is  the  only  example  of  an  Alpine  pass,  however, 

300 


LONG  ALPINE  TUNNELS 

which  is  traversed  by  rail  otherwise  than  through  a 
tunnel,  and  in  deciding  where  to  commence  boring 
they  are  guided  largely  by  three  considerations. 

First  of  all,  the  higher  the  mouth  of  the  tunnel 
the  more  likely  is  it  to  be  blocked  by  the  winter 
snows  ;  on  the  other  hand,  the  lower  it  is  the  longer 
will  the  boring  be  and  the  greater  will  be  the  heat 
encountered  when  doing  it.  Thirdly,  there  is  the 
question  of  gradient.  As  remarked  earlier,  the  route 
generally  becomes  more  and  more  steep  as  the 
summit  of  the  pass  is  approached,  and  this  fact,  too, 
has  to  be  taken  into  consideration. 

These  long  tunnels  are  usually  perfectly  straight. 
This  is  to  simplify  the  surveying  operations  by 
which  the  tunnel,  as  it  progresses,  is  steered,  as  it 
were. 

Just  consider  for  a  moment  what  this  means.  In 
the  case  of  the  Simplon  they  started  work  at  two 
points  over  twelve  miles  apart,  and  from  each  of 
these  points  a  tunnel  was  driven  in  the  direction  of 
the  other,  the  idea  being  that  they  should  join  up 
at  a  point  inside  the  mountain.  In  due  time  (after 
about  seven  years'  work)  they  met,  with  this  astound- 
ing result  :  one  tunnel  was  8  ins.  higher  than  the 
other  and  3|  ins.  to  one  side.  The  total  length  of 
the  tunnel  when  it  was  measured  right  through  was 
found  to  be  within  31  ins.  of  the  length  which  had 
been  calculated  over  the  surface  before  the  tunnel 
was  begun. 

To  put  it  another  way,  the  task  of  the  engineers 
was  to  draw  a  straight  line  from  one  point  six  miles 
long  towards  another  point  which  they  could  not 

301 


LONG  ALPINE  TUNNELS 

see,  and  they  were  only  8  ins.  wrong  when  they  got 
there. 

In  the  face  of  an  astonishing  problem  like  this  it 
is  not  surprising  that  they  make  the  tunnel  straight, 
as  that  simplifies  the  work  very  much  indeed.  As 
explained  elsewhere,  the  London  tubes  are  steered 
round  various  bends  and  corners,  but  the  length 
is  so  much  shorter  in  those  cases  that  the  problem 
is  a  much  easier  one. 

The  method  employed  is  to  survey  the  route  first 
of  all  upon  the  surface.  A  straight  line,  denoted  by 
suitable  marks,  is  carried  right  across  the  mountain 
from  one  starting  point  to  the  other.  Then  at  each 
end  of  this  line  there  is  set  up  an  observatory,  upon 
which  is  mounted  a  powerful  telescope,  so  placed 
that  it  can  first  of  all  be  directed  at  a  distant  point 
upon  the  surface  line  and  then  right  into  the  tunnel 
itself.  At  intervals,  as  the  work  proceeds,  an 
illuminated  mark  is  set  up  in  the  far  end  of  the 
tunnel  and  viewed  through  the  telescope,  and  by 
that  a  very  slight  deviation  can  be  detected  and  set 
right. 

These  long  tunnels  are  usually  on  the  whole  level, 
but  sloping  upwards  from  the  ends  towards  the 
middle  simply  in  order  that  they  may  drain  them- 
selves naturally.  In  this  respect  the  makers  of  a 
mountain  tunnel  have  a  great  advantage  over  the 
builders  of  a  subaqueous  tunnel,  for  in  the  latter 
case  pumping  has  to  be  used  upon  a  large  scale  and, 
as  in  the  well-known  case  of  the  Severn  Tunnel,  a 
mishap  may  result  in  the  whole  workings  being 
drowned  out  for  months. 

302 


LONG  ALPINE  TUNNELS 

An  inrush  of  water  is  by  no  means  unknown  even 
in  tunnels  high  up  in  the  mountains.  In  the  Simplon, 
for  instance,  a  spring  was  struck,  known  as  "  The 
Great  Spring,"  which  poured  10,500  gallons  per 
minute  into  the  workings,  and  a  hot  spring  which 
poured  in  3000  to  4000  gallons  every  minute  at  a  tem- 
perature of  114  degrees.  It  was  not  difficult  to  deal 
with  these,  however,  since  the  water  ran  out  naturally. 

The  necessity  of  making  the  tunnels  straight, 
however,  usually  makes  it  impossible  to  have  the 
entrances  at  the  most  suitable  points  upon  the 
mountain -side  for  the  trains  to  approach,  and  con- 
sequently where  the  train  enters  is  not  generally  the 
true  entrance  to  the  tunnel*  but  merely  the  entrance 
to  a  subsidiary  tunnel  which  curves  round  and  joins 
the  main,  straight  tunnel  some  distance  inside  the 
mountain. 

The  actual  work  of  boring  is  done  by  compressed 
air. 

There  are  two  kinds  of  "  rock-drill  "  used  for  the 
purpose.  These  are  machines  which  manipulate  a 
"  tool  "  termed  a  drill,  but  which  would  frequently 
be  better  described  as  a  chisel.  Some  of  these 
machines  turn  the  drill  round  and  round,  while 
others  employ  a  hammering  action.  In  either  case 
the  object  is  to  bore  a  hole  in  the  rock,  at  the  bottom 
of  which  can  be  placed  a  cartridge  of  explosive 
material  which,  when  fired,  will  break  down  the 
rock. 

Compressed  air  is  not  an  economical  means  of 
transmitting  power,  but  it  is  very  convenient  for 
work  like  this,  and  it  has  the  additional  advantage 

303 


LONG  ALPINE  TUNNELS 


in  a  hot  tunnel  that  the  air,  as  it  escapes  after  having 
done  its  work,  helps  to  ventilate  the  workings. 

In  one  case  an  ingenious  arrangement  was  adopted 
in  which  a  jet  of  water  under  high  pressure  was 
directed  upon  the  rock  about  to  be  blown  up,  with 
the  result  that  the  debris  was  at  once  carried  right 
away  from  the  face  and  the  men  were  able  to  resume 
drilling  operations  immediately  the  explosion  had 
taken  place,  instead  of  having  to  wait  for  the  broken 
rock  to  be  cleared  away.  Then  the  "  spoil "  is  carried 
away  in  small  trucks,  running  on  light  rails  laid  for 
the  purpose. 

It  must  not  be  thought,  however,  that  the  tunnel 
is  made  full-size  right  away.  A  small  tunnel,  called 
a  heading,  is  first  bored.  This  is  only  just  large 
enough  for  the  workmen  to  stand  up  in,  and  wide 
enough  for  the  necessary  two  lines  of  rail  for  the 
trucks.  Sometimes  the  heading  is  at  the  top  of  what 
will  be  the  finished  tunnel,  but  more  frequently 
it  is  at  the  bottom.  Vertical  shafts  are  then  bored 
upwards  from  the  heading,  and  from  these  the  rock  is 
attacked,  so  that  as  broken  down  it  falls  into  the 
heading,  whence  it  is  carried  away. 

The  use  of  compressed-air  machines  for  rock 
drilling  caused  a  great  saving  of  time  over  the  hand 
drilling  which  used  to  be  employed  for  such  work, 
but  even  with  the  best  appliances  a  speed  of  five  or 
six  yards  per  day  on  an  average  is  very  good  progress 
indeed. 

Much  depends  upon  the  nature  of  the  rock.  If  it 
is  soft  it  naturally  comes  away  most  quickly.  Hard 
rock  takes  more  time  to  bore  the  holes  and  less  of  it 

304 


LONG  ALPINE  TUNNELS 

breaks  away  with  each  explosion.  The  worst  rock 
of  all  to  deal  with,  however,  is  that  where  parts  are 
hard  and  parts  soft.  The  drill  then  probably  strikes 
a  spot  where  it  penetrates  both  sorts  at  once,  with 
the  result  that  the  hard  part  deflects  it  into  the  soft 
part  and  probably  either  causes  it  to  jam  tightly  or 
else  to  break. 

The  Simplon  Tunnel  was  made  for  a  single  line 
only,  the  intention  being  to  make  a  separate  tunnel 
for  a  second  line  as  soon  as  the  traffic  should  justify 
it.  The  two  headings  were  made,  however,  although 
only  one  was  enlarged  into  a  finished  tunnel.  At 
frequent  intervals  a  short  cross-heading  connected 
the  other  two,  and  this  was  found  very  useful  for 
ventilation  purposes,  for  air  could  be  driven  along 
one  to  find  its  way  through  the  cross-headings  and 
back  through  the  other,  thus  keeping  up  a  constant 
circulation. 

The  rocks  encountered  in  these  mountains  are  of  a 
very  varied  character,  but  in  most  cases  they  are 
firm  enough  to  need  no  support  other  than  their  own 
strength.  Where,  however,  they  are  so  soft  that  they 
tend  to  move  under  the  weight  of  the  mass  of  matter 
lying  above  them  they  need  to  be  strengthened 
temporarily  with  timber,  which  is  ultimately  taken 
out  gradually  and  replaced  by  masonry. 

Thus  some  tunnels  are  in  part  lined  with  masonry 
and  in  part  left  just  as  they  were  first  hewn  out  of 
the  solid  rock.  It  all  depends  upon  the  nature  of 
the  rock,  and  every  inch,  almost,  has  to  be  judged 
upon  its  own  merits. 

The  Simplon  Tunnel  is  lined  throughout,  but  there, 
u  305 


LONG  ALPINE  TUNNELS 

again,  the  thickness  of  the  lining  is  varied  according 
to  the  nature  of  the  rock.  In  some  parts  it  consists 
of  granite  masonry  5  ft.  thick. 

During  the  construction  of  the  St.  Got  hard  Tunnel, 
in  order  not  to  make  the  atmosphere  more  oppressive 
than  could  be  helped,  compressed-air  locomotives 
were  used  to  haul  the  trucks  of  broken  rock  out  from 
the  workings,  but,  of  course,  whether  for  construction 
purposes  or  for  actual  working,  electricity  is  pre- 
eminently the  best  form  of  traction  for  tunnels  like 
these. 

The  Simplon  Tunnel  is  worked  by  electric  loco- 
motives which  pick  up  their  energy  from  overhead 
wires.  The  system  employed  is  what  is  known  as 
the  "  three-phase  "  system,  in  which  three  separate 
alternating  currents  act  together.  It  requires  three 
separate  conductor  wires,  but  these  can  easily  be 
arranged  for  where  there  is  a  solid  masonry  roof 
from  which  they  can  be  suspended. 

One  other  feature  of  the  Simplon  Tunnel  should  be 
mentioned.  There  is  an  enlarged  portion  in  the  heart 
of  the  mountain,  to  accommodate  a  short  piece  of 
double  line,  where  two  trains  can  pass  each  other. 
But  for  this  it  would  have  to  be  worked  as  a  single 
line  section  twelve  miles  long,  but  by  this  means  it 
is  divided  into  two  six-mile  sections. 


306 


INDEX 


Accelerator  valve,  99 
"  Acid  "  and  "  Basic  "  pro- 
cesses, 132 
Air-locks,  232 
Air  pressure  in  the  "  tubes," 

238 

Alport,  Sir  J.,  18 
Alternating  current,  182 
"  Atomizing  "  oil,  90 
Automatic  stop,  The,  184 
"  Automatics,"  40 

Ballast,  117 
Ballast,  Laying,  293 
Basic  slag,  133 
Bessemer  process,  The,  129 
Blast  furnaces,  124 
Blast-pipe,  The,  65 
Block  system,  The,  159 
Block  telegraph,  171 
"  Blower,"  The,  66 
Boiler,  The,  60 
Boiler  shop,  The,  52 
Booking  office,  The,  20 
Bowstring  girders,  149 
Brake,  Types  of,  75 
Brass  foundry,  The,  56 
Bridge-yards,  141 
Bridges,  137 
Brunei,  24,  231 
Bus  bars,  261 
Bush  fires,  36 


Cabins,  Signal,  163 
Canada,  29 

Canadian  Pacific  Ry.,  Mak- 
ing the,  34 
Catch  points,  95 
Central  London  Ry.,  175 
Chairs  for  rails,  118 
Charging  machine,  134 
City  and  S.  London  Ry.,  175 
"  Clay  belt,"  The,  36 
Clayton's  fogging  machine, 

204 

Combinator,  The,  249 
Compound  engines,  73 
Compound  locomotives,  77 
Commutator,  The,  262 
Compound  v.  Simple,  85 
Compressed    air   machines, 

304 

Collectors,  268 
Condensation,  81 
Conductors,  266 
Connecting-rod,  The,  69 
Continuous  brake,  The,  94 
Contractors,  114 
Controller,  The,  218,  264 
Converter,  The,  129 
Cranes,  Electric,  49 
Crank,  The,  69 
"  Cropper,"  The,  142 
Cross-head,  The,  69 
44  Cupola,"  The,  56 


30? 


INDEX 


Currents,   Alternating    and 

direct,  182 
Cylinders,  The,  72 
Cylinders,  High-pressure,  83 

"  Dead  man's  handle,"  The, 

265 

Detectors,  170 
Diagrams,  220 
Dome,  The,  62 
Dorada  Ropeway,  The,  274 
Drain-cock,  The,  82 
Drilling  machines,  47 
Driving  wheels,  75 
Drop-forgings,  52 

Eccentric,  The,  70 
Ejector,  The,  100 
Electric  currents,  256 
Embankments,  110 
Engineer's  office,  The,  113 
Erecting  shop,  The,  58 
Escalators  or  moving  stairs, 

250 

Excavating  shield,  The,  238 
Exhauster,  The:  101 
Explosives,  Handling,  290 

"  Fettling,"  57 

Fire-box,  The,  62 

Flanging  presses,  52 

"  Fly-over,"  The,  120 

Fog,  201 

Fog  signals,  201 

"  Formation  level,"  117 

Furnaces,  Feeding  the,  134 

Ganger,  The,  120 

Gauge,    Curious   dimension 

of  the,  24 
Goods  traffic,  217 


Goods,  Transport  of,  19 
Gradients,  37 

Grading  machine,  The,  286 
Grand  Trunk  Pacific  Ry., 

284 

Grand  Trunk  Pacific,The,28 
G.N.R.  control  room,  The, 

219 

Great  Western  Ry.,  The,  24 
"  Grout,"  239 
Guard  rails,  119 

Hayes,  C.  M.,  29 
Hematite,  132 

Illuminated  diagrams,  198 
Impedance,  182 
Impurities  in  iron  ore,  127 
Indicators,  173,  244 
Ingot  moulds,  133 
Injector,  The,  74 
Inns,  20 
"Instrument   shelf,"    The, 

164 

Interlocking,  161 
Interlocking     apparatus, 

The,  165 

Iron  foundry,  The,  53 
"  Iron  man,"  The,  144 
Iron  ore,  124 

Ladle  for  molten  metal,  55 
Lathes,    their   fittings   and 

attachments,  40 
Lattice  girder,  The,  147 
"  Length  "  of  line,  120 
Light  railways,  25 
Link,  The,  71 
Locking  trough,  The,  166 
Lock  and  block,  179 
Locomotive  works,  39 


308 


INDEX 


Macdonald,  Col.  F.  R.,  90 
"  Machine  shop,"  The,  39 
Magazine    train    describer, 

247 

Manizales,  271 
Mariquita,  271 
Mild  steel,  123 
Motor  traffic,  22,  25 
Moulds  and  patterns,  54 

Navvy,  The,  115 
Non-return  valve,  98 

Oil  as  fuel,  88 

Oil  engines,  86 

Oil  v.  steam,  86 

Open  hearth  process,  The, 

130 
Opposition,  The  mistake  of, 

21 

Overlap,  The,  184 
Ozone  in  the  "  tubes,"  240, 

253 

Parcel  traffic,  20 
Parliamentary  powers,  111 
"  Patterns,"  54 
Permanent  way,  The,  120 
Permissive    tablet    system, 

156 

Pig  iron,  123,  127 
Pilot-man,  The,  151 
Pistol  hammer,  The,  53 
Piston,  The,  66 
Planing  machines,  45 
Plate-girder  bridges,  138 
Platelayers,  122 
Points  and  crossings,  119 
Points,  facing  and  trailing, 

168 

Points,    locking    and    un- 
locking, 155 


Poles  of  a  magnet,  The,  225 
Portage,  35 
Ports,  The,  67 
Power  signalling,  192 
Power-stations,  259 
Pressure  gauge,  The,  68 
Promoters    and    Directors, 

113 
Puddling  furnace. 

Radio-activity,  299 
Rail  with  rack,  23 
Rail  v.  Road,  26 
Railway,  Scheming  a,  110 
Rails,  122 
Ramp,  The,  207 
Raven  system,  The,  212 
Regenerative  furnaces,  181 
Regulator,  The,  63 
Relay,  The,  179 
Release  valve,  102 
Releasing  reservoirs,  102 
Reversing  the  engine,  69 
Rivets,  144 
Robinson,  Wm.,  176 
Rocky  Mountains,  37 
Roe,  J.  P.,  275 
Rolling  mills,  135 
Ropeways,  273 

Safeguards,  27 
Sand  blast  chamber,  The,  57 
Saws  for  cutting  metal,  142 
"  Scarab,"  The,  93 
Schedules  of  quantities,  113 
Selective  instruments,  222 
Semi-automatic    signalling, 

189 
Shearing  machine,  The,  58, 

142 
Shield,  The,  231 


3°9 


INDEX 


Shunting,  197 

Signalling,  Early,  160 

Simplon  tunnel,  The,  300 

Single  lines,  150 

Slag,  126 

Slide-valve,  The,  66 

Slotting  machine,  50 

Slough,  Accident  at,  212 

Smoke-box,  The,  65 

Soaking  pit,  135 

South-Western  Ry.,  The,  21 

Staff  system,  The,  151 

Stationmaster,  The,  216 

Steam-chest,  The,  67 

Steam  expansion,  80 

Steam  hammers,  50 

Steam  navvies  and  mechan- 
ical shovels,  115 

Steam  pressure,  78 

Steam-tightness,  68 

"  Stiffeners,"  140 

Stock  rail,  The,  119 

Stripper,  The,  133 

Super-heating  steam,  80 

Surveying,  30 

Surveying  parties,  hard- 
ships of,  35 

Surveying  the  route  of  a 
tunnel,  302 

Sykes'  audible  cab  signal, 
207 

Sykes,  W.  R.,  176 

Tablet  system,  153 
Tank,  The,  75 
Temperature  in  tunnels, 

298 

Templates,  141 
Tenders  and  Tenderers,  113 
Tension  or  pressure,  262 


Testing  bridges,  149 
Theodolite,  The,  235 
Third  class  carriages,  18 
Three  position  upper  quad- 
rant signal,  188 
Track  circuit,  The,  175 
Track-layer,  The,  291 
Tracks,  Temporary  and  per- 
manent 117 

Train  pipe,  The,  96,  100 
Transformers,  263 
Trappers  and  Indians,  334 
Travelling  in  old  times,  17 
Trestles  for  ropeways,  281 
Trevithick,  R.,  22 
Triple  valve,  The,  106 
"  Trough-flooring,"  145 
"  Tubes,"  The,  241 
Tunnels,  230,  295 

"  Underground,"  The,  241 

Vacuum    and    Compressed 

air,  96 
Ventilation  of  the  "  tubes," 

239 
Vertical  boring  mill,  50 

"  Walking  "  a  derrick,  148 
Water  in  tunnels,  303 
Western  Electric  Co.,  219 
Westinghouse    brake,    103, 

193 

"  Wet  "  steam,  62 
Wheels,  Types  of,  73 
Wrought  iron,  127 

Yellowhead  Pass,  The,  38 
Yerkes,  C.  J.,  242 


Mayflower  Press,  Plymouth,  England.     William  Brendon  &  Son,  Ltd. 
1921 


UNIVERSITY  OF  CALIFORNIA  LIBRARY, 
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